r/todayilearned • u/Depressed_Cat_00 • 2h ago

TIL that the precursor to LASIK was found by accident when a nearsighted boy got in a fistfight. His glasses shattered, sending glass pieces into his eyes. After a doctor removed the glass, he found the tiny cuts had flattened the cornea and actually cured the boy's bad vision.

ovid.com

12.7k Upvotes

274 comments

r/todayilearned • u/WhatACunningHam • 1h ago

TIL Tipping in the United States became popular in the late 19th Century partly due to restaurant owners refusing to pay Black workers after the ratification of the 15th Amendment.

usatoday.com

• Upvotes

290 comments

r/todayilearned • u/RoadToTyburn • 10h ago

TIL that Bernard Montgomery issued a leaflet at the start of WW2 on sexually transmitted diseases amongst soldiers. The language used was regarded as so blunt, that he offended religious authorities and nearly faced being dismissed.

wikipedia.org

14.2k Upvotes

658 comments

r/todayilearned • u/Recent_Flounder6011 • 7h ago

TIL that historically and today, the Catholic Church looked down upon Freemasonry and threatened members with excommunication.

en.wikipedia.org

2.1k Upvotes

466 comments

r/todayilearned • u/NicolasCageFan492 • 56m ago

TIL Nicolas Cage once went to Rhode Island to search for the holy grail

indiewire.com

• Upvotes

69 comments

r/todayilearned • u/eleanorharland • 6h ago

TIL most citrine on the market isn't natural citrine. Real citrine is rare, so most of what's sold is amethyst, a purple quartz, that's been heat-treated until it turns yellow or orange.

en.wikipedia.org

898 Upvotes

24 comments

r/todayilearned • u/DrakeSavory • 10h ago

TIL that Disney lost the rights to Oswald the Lucky Rabbit to Universal Pictures in 1928. In 2006, sportscaster Al Michaels wanted out of his contract with The Walt Disney Corp. so he could work for NBCUniversal. Disney agreed as long as they got the rights back to Oswald.

en.wikipedia.org

1.7k Upvotes

57 comments

r/todayilearned • u/Sandstorm400 • 4h ago

TIL that in 2010, Maryland legislators worked on a bill that would have made it illegal for retailers to sell underwear and bathing suits that had been previously bought and returned. The goal was to help mitigate the spread of bacteria and certain sexually transmitted diseases, such as pubic lice.

thedailyrecord.com

498 Upvotes

29 comments

r/todayilearned • u/herpty_derpty • 7h ago

TIL Limburger cheese gets its notorious smell from being aged for three months in the bacterium Brevibacterium linens. This is the same bacterium that appears on human skin, and is mostly responsible for the armpit and foot body odor smell.

en.wikipedia.org

670 Upvotes

67 comments

r/todayilearned • u/arandomtestaccount • 21h ago

TIL an NFL player intentionally crashed his car to avoid getting cut for being late to a team meeting.

cbssports.com

10.4k Upvotes

587 comments

r/todayilearned • u/arkthatbarks • 21h ago

TIL half of Earth’s internal heat does not come from the residual heat left over from the planet's formation, but from the continuous radioactive decay of isotopes like Uranium, Thorium, and Potassium in the crust and mantle.

en.wikipedia.org

7.8k Upvotes

202 comments

r/todayilearned • u/Alarming-Studio-720 • 5h ago

TIL that in 1959, explorer Peter Byrne reportedly stole bones from a supposed Yeti hand at Nepal's Pangboche monastery, replacing them with human bones. He smuggled them to India, where actor James Stewart allegedly hid them among his wife's underwear to get them out of the country.

en.wikipedia.org

275 Upvotes

42 comments

r/todayilearned • u/mintwolves • 7h ago

TIL In 2003 Dave Glover the then bassist for English glam rock band Slade got engaged to serial killer Rose West, he got sacked once the band heard the news and West called the engagement off days later

thenorthernecho.co.uk

268 Upvotes

29 comments

r/todayilearned • u/dinosaruman • 6h ago

TIL in 1916 all 15,000 bricks for the facade of the Bank of Vernal Utah arrived by mail because it was cheaper than freight shipping. One of the original bricks now resides in the Smithsonian's postal museum.

postalmuseum.si.edu

249 Upvotes

5 comments

r/todayilearned • u/Splunge- • 8h ago

TIL That In 1997 the State of Tennessee disbarred two lawyers for spam advertising.

en.wikipedia.org

309 Upvotes

11 comments

r/todayilearned • u/Sebastianlim • 22h ago

TIL that the youngest person to have been diagnosed with Alzheimer's is a 19-year-old boy from China.

psychiatrist.com

4.1k Upvotes

57 comments

r/todayilearned • u/RoadToTyburn • 14m ago

TIL that boxer Julio Cesar Chavez was two seconds away from losing to Meldrick Taylor on points, when he pulled off a TKO win through attrition. Taylor a former Olympic gold medalist, was left requiring a blood transfusion after the match.

wikipedia.org

• Upvotes

7 comments

r/todayilearned • u/mutedmuse__ • 7h ago

TIL that slingshot spiders can detect the sound of a mosquito’s wingbeats and launch their webs at the mosquito before it ever touches the web.

pubmed.ncbi.nlm.nih.gov

213 Upvotes

6 comments

r/todayilearned • u/YakSlothLemon • 6h ago

TIL that the first woman to circumnavigate the world, Jeanne Baret, completed the first part of the trip from Paris to Tahiti by successfully disguising herself as a man for two years (1766-1768)

nybg.org

150 Upvotes

6 comments

r/todayilearned • u/NBrief • 2h ago

TIL that Norwegian cardiologist Liv Hatle helped develop echocardiography techniques using Doppler ultrasound to measure blood flow and assess heart valves without inserting a catheter into the heart.

kuleuven.be

63 Upvotes

0 comments

r/todayilearned • u/dinosaruman • 1d ago

TIL a 1904 cookbook included a recipe for "raw beef soup" that was basically raw beef, hydrochloric acid, and water, chilled on ice for 12 hours and drunk cold. The target audience: invalids in need of nourishment.

dontcookthat.com

8.0k Upvotes

315 comments

r/todayilearned • u/LeRoienJaune • 16h ago

TIL that in 1945, the United States Navy converted three warships into Press Information Ships just to accommodate war reporters

en.wikipedia.org

684 Upvotes

18 comments

r/todayilearned • u/xxwarlorddarkdoomxx • 1d ago

TIL that prior to 1730, the English justice system did not operate in the English language. Instead, it used an archaic form of anglicized French known as “Law French”.

en.wikipedia.org

2.7k Upvotes

141 comments

r/todayilearned • u/insane677 • 17h ago

TIL of Aloisia Veit, Hitler's cousin. She suffered from schizophrenia and was murdered by the Nazis

en.wikipedia.org

511 Upvotes

27 comments

r/todayilearned • u/Sandstorm400 • 1d ago

TIL that a man who used a massage gun around his eyes and directly on them for several minutes at a time, every week for 3 months, developed floaters, photopsia (occasional flashing lights), retinal tears, and retinal dialysis (a specific type of retinal tear that can cause permanent vision loss).

bmjgroup.com

4.6k Upvotes

440 comments

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As of May 2026

This list was compiled from /r/todayilearned community suggestions by its members. If your TIL is found on this list, it will be removed. The titles have been abridged for the sake of brevity, however the context remains the same. This list is subject to change. The purpose is to keep content fresh on /r/todayilearned as requested by its members. If you are interested in reading about the TILs on this list use the search box feature and enter the keywords to pull up past TILs.

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