Do you know how Napoleon’s bitter childhood classmate took his sweet revenge after 15 long years? Or what the Celtic custom of “handfasting” meant for couples back in the day?
If you want the answers — and plenty more fascinating trivia along the way — keep reading. We’ve collected some of the most surprising and interesting facts that people recently shared on r/todayilearned.
Whether you love history, science, or pop culture, this list has something to spark everyone’s curiosity. Who knows, you may just find a new favorite conversation starter to impress your friends.
#1
TIL coffee (the drink) wasn’t invented until the 1400s in Yemen, who maintained a virtual monopoly on it until Dutch smuggled the plant to Java in the 1600s.
Image source: Ishmael_1974, Dilara Hazıroğlu
#2
TIL Adam DeVine was hit by a cement truck at age 11, breaking every bone in his legs. He spent two weeks in a coma, underwent 26 surgeries, and used a wheelchair during recovery. Today, he supports Children’s Miracle Network Hospitals and regularly visits children in hospital.
Image source: haddock420, TheoVon
#3
TIL Michael Jordan would often bet on Jumbotron cartoon races with a Bulls security guard during games, but nearly always won because he got the winners from arena staffers in advance.
Image source: RedditIsAGranfaloon, Carmine Galasso
The more you learn, the more you will realize how little you actually know. It is completely natural to feel overwhelmed by the sheer amount of information out there. After all, the human brain has a physical limit to how much data it can store and retrieve.
Even with infinite memory, a single human lifespan is far too short to read, experience, or process every piece of information that exists — or every new detail created every second.
#4
TIL about 2-Nonenal, the natural chemical found on skin that is responsible for the distinct “old person smell.” It typically appears once humans turn 40 and is described as musty, greasy, or grassy. It is not hygiene related, as it cannot be washed away with standard soap and water.
Image source: unravelledthought, Tima Miroshnichenko
#5
TIL that at military school, Napoleon had a bitter classmate named Phélippeaux whom he constantly traded insults and fistfights with. 15 years later, Phélippeaux masterminded the defense at the Siege of Acre, dealing Napoleon the first major defeat of his military career.
Image source: Neil118781, Jacques-Louis David
#6
TIL The Celtic custom of “handfasting” allowed couples to enter into a trial marriage lasting one year and a day. If the relationship didn’t work out, the couple could separate without any further attachment. Successful couples would marry.
Image source: TangerineDream92064, Feyza Yıldırım
It’s also impossible to know everything, because humanity as a whole has barely scratched the surface of our own world, let alone the vastness of space.
For instance, according to recent data from the Seabed 2030 ocean mapping initiative, over 71% of the Earth’s global seafloor still remains unmapped using modern high-resolution technology.
In fact, scientists estimate that less than 0.001% of the deep ocean floor has ever been directly seen by human eyes.
We still have so many other major mysteries to solve. Scientists are still trying to figure out what happened before the Big Bang, how life first started, and what consciousness actually is.
#7
TIL the Olympic Games used to be strictly amateur-only. Abusing this, the Soviet Union would enter athletes who were nominally working in some profession, but in reality were all paid to train on a full-time basis, leading to their dominance during the 70s and 80s.
Image source: ODaferio, Anastase Maragos
#8
TIL that the “zombie-ant” fungus (Ophiocordyceps) does not control ants by invading their brains. Instead, it leaves the brain completely intact while directly encircling and seizing control of their muscle fibers like a biological puppet.
Image source: Fairytlly, Susan Wilkinson
#9
TIL that in 2016, a Chinese artist spent 3 days building a $15,000 LEGO statue or Nick Wilde from Zootopia. Shortly after it was put on display, a 4-year-old boy accidentally knocked it over, destroying it. The artist refused an offer of compensation from the parents.
Image source: Sebastianlim, John Doyle
Taking that extra step to learn new things actually rewires your brain to handle life’s challenges better.
Researchers at Columbia University’s Zuckerman Institute recently tested this idea with mice in simple mazes. In their experiments, the scientists constantly changed the rules for where the mice could find rewards. But there was a catch: before entering the maze, some mice had time to explore unfamiliar rooms or meet new mice, while others stuck to their usual routine. The mice that enjoyed fresh, new experiences right before the test solved the shifting maze much faster.
The results prove that stepping out of your comfort zone and learning something new primes the brain, making it far easier to adapt when circumstances suddenly change.
#10
TIL that Michelangelo and Leonardo Da Vinci were rivals. They’ve actually met on several occasions and even worked on the same wall, side by side.
Image source: THEMIGHTYKITEMAN, Liisbet Luup
#11
TIL that the actress Jodie Foster is fluent in French to the degree that she dubs herself in French-language versions of most of her English-language films. She attended the Lycée Français de Los Angeles, a French-language school.
Image source: johnsmithoncemore, Mohamed hamdi
#12
TIL that the first television rerun was an episode of I Love Lucy in 1952; before that, TV episodes were aired just once, and never again.
Image source: Fragrant-Upstairs932, CBS Television
There is no age limit on when you should stop picking up new facts — learning is a lifelong journey that keeps the brain sharp at every stage of life. As we grow into adulthood, busy schedules and set routines can make it harder to maintain that same sense of wonder.
However, curiosity is like a muscle: the more you use it, the stronger it gets. Science shows that adult brains retain neuroplasticity, meaning they can form new neural connections and continue growing no matter how old you are.
You’ve already taken the first step toward building that habit just by scrolling through this list. The secret is simply adopting a child’s open-minded approach to the world around you.
“Children don’t typically say, ‘this is not relevant to me, I’m not going to learn it.’ So typically when they see something, they are curious, they just want to learn whatever comes their way. And so as adults, we can also try to have more of that kind of attitude as well. So don’t dismiss things as irrelevant and just take in what you can,” says Dr. Rachel Wu, an associate professor of psychology at the University of California, Riverside.
#13
TIL the population of the NYC metropolitan area makes up 7.9% of the total US population. The city alone is 2.5% of the country’s population.
Image source: named_mark, Chris
#14
TIL that Leif Erikson was a Norse explorer who is thought to have been the first European to set foot on continental America, approximately half a millennium before Christopher Columbus.
Image source: 247Twunk, Christian Krohg
#15
TIL that MIT has the world’s largest public collection of science fiction. Anyone can browse the MIT Science Fiction Society’s library, and anyone can become a member to borrow books.
Image source: TMWNN, Yuanda “Darian” Shen
Learning new facts and keeping your mind active pays off as you grow older. A 15-year study from the Karolinska Institutet shows that building a strong mental reserve can delay memory loss and protect your brain over time.
Older adults who challenge themselves with complex tasks — like learning a new language or picking up a tricky hobby — stay sharp. More importantly, these mental workouts help people live independently for much longer.
#16
TIL that despite their name, it is biologically impossible for a centipede to be born with exactly 100 legs because a genetic quirk dictates they always have an odd number of leg pairs.
Image source: mvincen95, Marcus Lange
#17
TIL whales produce milk as thick as toothpaste so that it doesn’t disperse into the water like it would as a liquid.
Image source: KindSecretary6383, Ivan Stecko
#18
TIL that Frasier the Lion was given to Lion Country Safari in his old age and very ill. The lionesses there took care of him even to chewing his food since he was toothless and holding him up to walk. He fathered 35 cubs with them and the California State Assembly named him Father of the Year.
Image source: DrakeSavory, Kebs Visuals
When curiosity takes hold, your brain turns on its internal reward system. It releases a flood of dopamine — the chemical linked to feelings of pleasure and reward. This surge creates a rush of activity between the brain’s pleasure center (the nucleus accumbens) and its memory hub (the hippocampus). As a result, research from UC Davis shows that curiosity acts like a mental superpower, prepping your brain to soak up and retain new information much faster.
For instance, when you hear about Napoleon trading insults and fistfights with his bitter military school rival, the juicy feud immediately grabs your attention. Because that initial spark gets your brain excited, you are far more likely to absorb and remember the more important historical details — like how the classmate later masterminded the defense at the Siege of Acre 15 years later.
#19
TIL chewing gum is not biodegradable because it is made from synthetic polymers and plastics.
Image source: dr–moreau, Katy Walters
#20
TIL that no fatal accidents have ever occurred with Australian passenger jets; including all flights to/from Australia, as well as all Australian-run companies.
Image source: kahlzun, Pascal Borener
#21
TIL that in 1963 several cows were carried into the air by a tornado in Illinois. They survived but “acted strangely for several days”.
Image source: mining_moron, serap sağbaş
Because our knowledge is so limited, we should treat even a little bit of information with caution. A small amount of knowledge on a topic often creates false confidence, causing people to mistake a tiny fraction of data for complete mastery.
So, instead of assuming you know everything about a subject, the best approach is to keep digging deeper. Once you gain a bit more context, you will quickly recognize how much there is left to explore.
That is why reading a quick fun fact is only the first step — if a piece of trivia piques your interest enough to pass it along, take a moment to dig into the whole story first.
#22
TIL Jakarta, Indonesia, is now the world’s most populous city, with a population of 42 million people. Dhaka, Bangladesh, with a current population of 36 million, is expected to surpass Jakarta by the mid century, while Tokyo is expect to drop to 2.7 million residents.
Image source: ScienceTeacher1994, Dapur Melodi
#23
TIL that walking after exercise activates the calf muscle pump, helping return blood to the heart and reducing the risk of a sudden drop in blood pressure.
Image source: SeesawStock9306, Ketut Subiyanto
#24
TIL that Checkers has been a solved game for almost 20 years. Optimal play is unbeatable, and two opponents playing optimally always reach a stalemate.
Image source: PeasantLich, Tai’s Captures
#25
TIL that when Gustave Eiffel built the Eiffel Tower in 1889, he reserved a small apartment for himself near the top. It had wallpaper, comfortable furniture, and even a piano. He turned down huge offers from Paris’s elite to spend a night there, inviting only select guests such as Thomas Edison.
Image source: haphazard44, Jari Volpato
#26
TIL a finance worker at a multinational firm was tricked into transferring $25 million to scammers after joining a video conference call where every single other participant—including the company’s CFO and several of his recognized coworkers—was an AI-generated deepfake.
Image source: Neebez, Mikhail Nilov
#27
TIL Tobey Maguire never told the producers of Spider-Man (2002) about his claustrophobia. He nearly blacked out during a plaster body cast, forcing the costume makers to alert the producers themselves. Maguire then took a prototype suit home to train himself to perform in it.
Image source: MOinthepast, IMP Awards, Columbia Pictures.
#28
TIL Napoleon III escaped from a fortress where he was serving a life sentence by disguising himself as a laborer and walking through the main gates carrying a large plank over his shoulder to hide his face. Six years later, he became Emperor of France.
Image source: 1salt1pepper, Alexandre Cabanel
#29
TIL Christian Bale has been driving a 2003 Toyota Tacoma (that was bought secondhand) for over two decades.
Image source: TragicHero84, Jack Schickling
#30
TIL Highway hypnosis, also known as white line fever, is an altered mental state in which an automobile driver can drive safely and correctly over long distances without consciously remembering having done so.
Image source: AetheriaNox, Irina Iriser
#31
TIL Dublin’s Cineworld had to pay a fired worker €20,000 ($25,000) in compensation over a €1 snack dispute. The employee, Carl Meade, was sacked for gross misconduct after accidentally paying for a regular hot dog but taking a large, which the court later ruled was an innocent mistake.
Image source: Adventurous-Root
#32
TIL an ancient lake is a lake that has consistently carried water for more than one million years. There are only 20 ancient lakes in the world and 12 of them have existed for more than 2.6 million years.
Image source: AetheriaNox
#33
TIL that from 2013 to 2015 a maths forum user called “Cleo” posted correct answers to integrals that had stumped everyone, often within hours, never showed any working, and said a medical condition stopped her explaining. In 2025 Cleo was revealed to be Vladimir Reshetnikov, a software developer.
Image source: eleanorharland
#34
TIL a guy called Frank built a wall along the Alpine Fault in the South Island of New Zealand to test if the earthquakes are small and often or big and rare. It hasn’t moved a millimeter in 64 years.
Image source: SUMBWEDY
#35
TIL the ancestors of the Māori people arrived in New Zealand around 1350 AD, only ~300 years before their contact with Europeans.
Image source: OttawaOsprey
#36
TIL that Joseph Laroche, the Titanic’s only documented Black passenger, gave up first-class passage on another liner for second class on the Titanic because the other ship wouldn’t let children dine with their parents. His wife and daughters survived the sinking. He did not.
Image source: Upstairs_Drive_5602
#37
TIL A 2016 NIH study found that most “Biggest Loser” contestants studied quickly regained their lost weight, while their metabolisms remained slowed even six years later and their bodies burned hundreds fewer calories daily than expected.
Image source: carboncopy95437
#38
TIL a man with no heirs left more than €10 million to a Normandy village of 1,800 people that he’s not thought to have ever visited. The only connection anyone could find was that it shared his surname: Thiberville.
Image source: eleanorharland
#39
TIL when Spitfire and Hurricane engines kept cutting out in dives during WW2, the fix was a simple washer in the fuel line designed by Beatrice Shilling, an engineer who also raced motorbikes at Brooklands at over 100mph. It became known as “Miss Shilling’s orifice”.
Image source: eleanorharland
#40
TIL that in 1872, two conmen planted $20,000 worth of gemstones in Wyoming and fooled wealthy investors into believing they’d discovered a massive diamond field.
Image source: SaltyDogBill
#41
TIL that in a landmark 1988 study proving aspirin saves lives in heart attacks, the frustrated authors included patients’ star signs in their subgroup analysis to protest reviewers who demanded endless data slicing. The results suggested aspirin was ineffective in Libras and Geminis.
Image source: vaime
#42
TIL that the average American armed forces inductee in WWII was 26 years old, 5′ 8″ tall, 144 pounds, and had 9 years of formal schooling.
Image source: MrMojoFomo
#43
TIL that British stole tea from China through Robert Fortune who shaved his head, wore local Chinese clothing (including a pigtail), and posed as a wealthy official from a distant province to hide his accent. And stole 20,000 seeds to break China’s monopoly on tea by growing it in then British India.
Image source: Downtown_Ebb9600
#44
TIL about the indigenous Khasi people of Northeast India. They practice a strict matrilineal system where children take their mother’s surname, husbands move into their wife’s family home (the mother-in-law’s home), and the youngest daughter inherits all family wealth and ancestral property.
Image source: nouveaux_sands_13
#45
TIL that because most Icelanders use patronymic surnames, the most common hereditary family name in Iceland is Nguyen.
Image source: virora
#46
TIL that Jordan Nagai, who played Russell in Up, wasn’t originally intending to audition for the role. He only came to support his older brother, who was auditioning.
Image source: Sebastianlim
#47
TIL On average, a kidney transplant from a living donor lasts about 15 to 20 years, and a kidney from a deceased donor lasts 8 to 12 years.
Image source: AetheriaNox
#48
TIL an NFL player intentionally crashed his car to avoid getting cut for being late to a team meeting.
Image source: arandomtestaccount
#49
TIL that Dutch employers must keep paying sick employees for up to 2 years, at least 70% of their salary, often topped up to 100% for the first year by collective agreements.
Image source: alrightfornow
#50
TIL that during production of Iron Man (2008), the character was so obscure that 30 writers passed on the project. Even when a script was written, requests for rewrites were met with more refusals.
Image source: Sebastianlim
#51
TIL that Harry Potter and the Order of the Phoenix became the first English-language book to be on top of France’s bestseller list because impatient fans bought it in English while waiting months for the French translation.
Image source: carboncopy95437
#52
TIL that Shazam (Billy Batson), published by Fawcett comics was the #1 selling comic-book, and was lapping Superman in sells, until DC put a stop to it – taking them to court and claiming he was a Superman ripoff.
Image source: _railroaded_
#53
TIL that an American physicist predicted that horses will reach their top trotting speed in the year 2158, trotting 1 mile in 99 seconds.
Image source: Miner_Guyer
#54
TIL In 2012, an Irish mother delivered her first twin prematurely, and her contractions stopped. This allowed the second twin to stay safely inside the womb for another 87 days. This rare occurrence is known as a delayed-interval delivery. It broke the previous world record of 84 days.
Image source: TooKreamy4U
#55
TIL WWII General George S. Patton believed in reincarnation and claimed he had fought in wars for thousands of years. He believed he had lived as a Roman soldier, a Viking, a knight at Agincourt, and even a cavalryman under Napoleon, saying he had lived many military lives.
Image source: Alarming-Studio-720
#56
TIL that in 1943, a U.S. Navy destroyer accidentally fired a live torpedo at the battleship carrying President Roosevelt. The USS Iowa managed to evade the torpedo, and the destroyer’s crew initially tried to warn the battleship using signal lamps before breaking radio silence to alert them.
Image source: anon
#57
TIL of Alfred Gwynne Vanderbilt, a Gilded Age millionaire who lost his life when the RMS Lusitania sank in 1915, after giving his own life vest to a young mother and her baby. He couldn’t swim and he knew that there were no other lifeboats available at the time. He was 37. The woman & her child survived.
Image source: Sapphire-Crystal
#58
TIL that the population of Detroit, Michigan has grown for 3 straight years since 2023, reversing a trend of 65 consecutive years of population loss from 1957 to 2022. It currently sits at America’s 26th largest city with 650,000 residents.
Image source: worlds_of_kings
#59
TIL that mushrooms and crabs use the exact same base material (chitin) for structure. Mushrooms stay soft and edible because their chitin is mixed with flexible proteins, while crustaceans use minerals to calcify their chitin into a hard, brittle exoskeleton.
Image source: palmerry
#60
TIL that the Marvel comic “Secret Wars” got its name after focus groups found that children responded positively to the words “secret” and “wars”.
Image source: Sebastianlim
#61
TIL the Shakespearean actress Ellen Terry went to a school production of Julius Caesar in London in 1917 and wrote in her diary: “The small boy who played Brutus is already a great actor.” That 10-year-old boy was Laurence Olivier.
Image source: RunDNA
#62
TIL Vincent van Gogh declared his love and proposed marriage to his cousin Cornelia “Kee” Vos-Stricker, to which she replied “No, nay, never.” Months later, Gogh traveled to Amsterdam to meet her, but she refused seeing him. Her parents described his persistence as “disgusting”.
Image source: Speed_Spin
#63
TIL that in 2020, Justin Montney lost his fiancée, Alexis-Athena Wyatt, in a car crash. When he attempted to get a refund from the photography company he had hired for their wedding, they not only refused but released a statement mocking him.
Image source: Sebastianlim
#64
TIL that in the 1800s the American dairy industry used to sell milk thinned with water. They recolored the resulting bluish-gray liquid with dyes, chalk, or plaster dust, and faked the look of cream using pureed calf brains. The milk was often filled with bacteria and preserved with embalming fluid.
Image source: Do_Not_Go_In_There
#65
TIL Metal Gear Solid 4 (2008) holds the world record for the longest cutscene in any video game, with a single continuous cutscene of 71 minutes and a total of over 8 hours of cutscenes.
Image source: Guitar-String
#66
TIL Salivating before vomiting is a way for your body to protect your teeth from thr incoming stomach acid.
Image source: LeviBrown55
#67
TIL about the Cannonball Loop, an infamous enclosed water slide where some riders would experience lacerations while on the slide. After investigation, it was determined the lacerations were a result of embedded teeth in the interior wall of the slide from other riders’ accidents.
Image source: Ambitious_Tap_8998
#68
TIL that two brothers spent eight years recreating the entirety of Toy Story 3 in stop motion. The film was released on YouTube in 2020 with Disney’s permission.
Image source: Sebastianlim
#69
TIL about a Japanese general who thought that his war crimes sentence was too light, so built his own prison in his garden.
Image source: Bitter_Surprise_8058
#70
TIL a man was diagnosed with endocarditis and suffered heart damage, leading to a 7-hour open-heart surgery due to an infection caused after he unsuccessfully tried to remove a stuck piece of popcorn from his mouth with a pen lid, a toothpick, a piece of wire, and a metal nail.
Image source: Sandstorm400
#71
TIL: The prefrontal cortex being fully developed at age 25 is a myth.
Image source: hairdothrowaway
#72
TIL there’s a pirate radio station in Montclair, NJ, that has played Boyz II Men’s “I’ll Make Love To You” on a 24-hour loop since 2010.
Image source: solidgoldrocketpants
#73
TIL on average, an SR-71 could fly just once per week because of the lengthy preparations needed. A total of 32 aircraft were built; 12 were lost in accidents, none to enemy action.
Image source: flying_ina_metaltube
#74
TIL that comic books from the 1960s and 1970s could have ads for squirrel monkeys and that kids could order them. In one instance, a boy ordered a squirrel monkey after seeing an ad in a Spider-Man comic. After it arrived, the monkey gnawed on the boy’s arm, which resulted in him getting 28 stitches.
Image source: Sandstorm400
#75
TIL the 50 million Francs of the Louisiana purchase were used to finance preparations for a 200k man army to invade Great Britain. The United States had partly funded the purchase by a loan from Baring Brothers of London, which meant that a British bank was indirectly funding an invasion of Britain.
Image source: MonkeyFox29
#76
TIL Disneyland originally used real human skeletons provided by the UCLA Medical Center in the Pirates of the Caribbean ride because 1960s fake bones weren’t convincing enough.
Image source: Tall-Run-5511
#77
TIL that while casting Kung Fu Hustle (2004), Yuen Qiu wasn’t auditioning for the role of the Landlady. She had only accompanied a friend to his audition. Director Stephen Chow spotted her smoking, recognized her, and cast her after spending over a year searching for an actress for the role.
Image source: MOinthepast
#78
TIL David Vetter “Bubble Boy” spent his entire life in a bubble, he suffered from severe combined immunodeficiency, and eventually passed away at the age of 12.
Image source: jpw0w
#79
TIL about Steve Eimers, otherwise known as the “Guardrail Guy,” who has spent years finding and documenting improperly installed guard rails after his daughter lost his life in a car accident.
Image source: KilluhCrocz
#80
TIL that Mark Twain was a guitar player. He apparently never mentioned this in his public writing or speeches. He played on the same guitar all his life, one made in 1835, the year of his birth, and took it everywhere on his travels. He learned from his sister, who also taught him piano.
Image source: sayskoombah
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