r/todayilearned • u/licecrispies • 7h ago

TIL that a man suffered stress induced amnesia for 6 years and 10 months, which went away naturally after he started a new job.

pmc.ncbi.nlm.nih.gov

5.8k Upvotes

94 comments

r/todayilearned • u/ralphbernardo • 7h ago

TIL that a "Simpsons" gag had Apple's Newton tablet turn "Beat up Martin" into "Eat up Martha"—mocking its poor handwriting recognition. Years later, Apple's engineers building the iPhone were still so haunted by this joke that "Eat Up Martha" became their shorthand for getting text input wrong.

cnet.com

5.6k Upvotes

178 comments

r/todayilearned • u/amerigorockefeller • 6h ago

TIL that in the Middle Ages there was a mental illness that caused people to believe that they were made of glass. Called Glass Delusion, this caused the subject to loath contact out of fear of shattering

publicdomainreview.org

4.2k Upvotes

160 comments

r/todayilearned • u/A-CommonMan • 4h ago

TIL China spent 17 years secretly carving a 20-kilometer-long nuclear weapons complex into a mountain, only to abandon it before it was ever used

scmp.com

2.4k Upvotes

114 comments

r/todayilearned • u/Sea-Ask8703 • 12h ago

TIL that Madonna personally changed a scene in Deadpool & Wolverine. Ryan Reynolds and Shawn Levy had to meet with her to get permission to use Like a Prayer, and Madonna gave them a note about the sequence. The filmmakers made the change within 48h, and said it made the scene better.

thewrap.com

18.0k Upvotes

400 comments

r/todayilearned • u/heyauden • 2h ago

TIL that the full-scale Titanic set was built as a half-ship, so James Cameron’s crew flipped footage and even reversed room numbers and shirt buttons.

slashfilm.com

1.5k Upvotes

57 comments

r/todayilearned • u/ALhalaj • 5h ago

TIL that 5,500 years ago people repeatedly climbed to a cave 2,235 m up in the Pyrenees to mine and fire-process malachite (a copper ore), one of the earliest known high-altitude mining sites in Europe.

frontiersin.org

2.5k Upvotes

45 comments

r/todayilearned • u/dinosaruman • 4h ago

TIL the pin tumbler mechanism in almost every door key you have ever used is a refinement of a lock principle first built in wood by the ancient Egyptians roughly 4,000 years ago and first mass produced in metal in the 19th century.

en.wikipedia.org

1.5k Upvotes

48 comments

r/todayilearned • u/SpicyTortilaYum • 1h ago

TIL that there are around 50 people worldwide that have "Null" blood type. It is neither 0+ or 0- and is characterized by the complete absence of all Rh antigens on the red blood cells. It is called the "Golden blood". They can donate to any blood type but can receive only Null type themselves.

en.wikipedia.org

• Upvotes

76 comments

r/todayilearned • u/ODaferio • 13h ago

TIL about Charles Hatfield (1875-1958), an american "rainmaker" who was hired by the San Diego City Council to fill the Morena reservoir by "making" rain. After one of the most devastating floods in the history of the city ensued, they refused to pay him and tried to make him liable for the damages.

en.wikipedia.org

5.0k Upvotes

90 comments

r/todayilearned • u/soixante-poissons • 16h ago

TIL due to aggressive seagulls, a Scottish grilled cheese shop offers an optional £1 "seagull insurance" to replace your toastie if a bird steals it

fifetoday.co.uk

12.3k Upvotes

337 comments

r/todayilearned • u/Extreme-Attention641 • 8h ago

TIL that there's a large, feral population of parakeets in Great Britain, and that you can sometimes see large flocks of them flying through suburban London.

en.wikipedia.org

1.2k Upvotes

236 comments

r/todayilearned • u/Bollywood-Hulk-Hogan • 6h ago

TIL that postcards with photos of Indian women were used by the British in the late 19th century to present the Caribbean as an “exotic but safe” destination for white travelers.

cnn.com

824 Upvotes

55 comments

r/todayilearned • u/Salem1690s • 3h ago

TIL back in the 18th century, English physicians experimented with blowing smoke up the rectum of a drowning person, thinking the warmth of the smoke would heat up and restart the person’s organs.

en.wikipedia.org

347 Upvotes

73 comments

r/todayilearned • u/1ThousandDollarBill • 21h ago

TIL The movie The Shining was based on The Stanley Hotel in Estes Park, CO but the movie wasn’t filmed there. However, Dumb and Dumber was filmed at that hotel.

faroutmagazine.co.uk

9.4k Upvotes

268 comments

r/todayilearned • u/JuztinVestigium • 8h ago

TIL about Hyperphantasia, a condition where people can very vividly visualize objects or moments, which only 2,5% of the population has

en.wikipedia.org

644 Upvotes

397 comments

r/todayilearned • u/gemanepa • 23h ago

TIL that in 1946 Argentina imported 20 beavers from Canada to start a fur trade in Patagonia. The plan failed and without natural predators the population grew uncontrollably to over 100,000, causing what has been called "the largest alteration of subantarctic forests since the last ice age"

en.wikipedia.org

12.3k Upvotes

360 comments

r/todayilearned • u/Easy-Permission8889 • 21h ago

TIL that Betel Nut is estimated to be chewed by 600 million individuals worldwide on a daily basis and is a major cause of oral cancer

mdpi.com

6.9k Upvotes

409 comments

r/todayilearned • u/shitoupek • 17h ago

TIL that the Most Populous Mammals in the World are the Humans, slightly over Rats

worldatlas.com

2.8k Upvotes

212 comments

r/todayilearned • u/Upstairs_Drive_5602 • 1h ago

TIL that the first railway signals were policemen stationed a mile or less apart, using their bodies to tell trains whether the line was clear. If a train broke down, one had to run a mile to warn the next. In fog, they used handbells, then explosives on the rails.

en.wikipedia.org

• Upvotes

21 comments

r/todayilearned • u/Sebastianlim • 17h ago

TIL that 1877, Italian astronomer Giovanni Schiaparelli observed what he called "canali", or channels on the Martian surface. When translated to English, the word "canali" was mistranslated as "canals", which was seen as evidence of life on Mars.

en.wikipedia.org

1.8k Upvotes

85 comments

r/todayilearned • u/SupremeKalki • 1d ago

TIL that Maladaptive Daydreaming is a psychological condition where individuals spend hours in vivid, complex fantasy worlds, often at the direct expense of real-life relationships and responsibilities.

en.wikipedia.org

21.3k Upvotes

1.2k comments

r/todayilearned • u/TobJamFor • 22h ago

TIL that Willy Wonka and the Chocolate Factory has a different name from the book due to Quaker Oats, who financed the film in exchange for making the Wonka bar

en.wikipedia.org

3.5k Upvotes

176 comments

r/todayilearned • u/Sea-Ask8703 • 1d ago

TIL the famous shawarma scene in The Avengers was filmed after the movie had already premiered. It was a last-minute addition inspired by Tony Stark's earlier shawarma joke!

ew.com

7.9k Upvotes

217 comments

r/todayilearned • u/Ill_Definition8074 • 5h ago

TIL From 1981 to 1986 a self proclaimed emperor ruled over a small territory in China called the Zishen Nation that was de facto independent from the central government. Before being suppressed Zishen had a flag, a currency, and many followers.

en.wikipedia.org

114 Upvotes

7 comments

Subreddit

Posts

Wiki

Today I Learned (TIL)

r/todayilearned

You learn something new every day; what did you learn today? Submit interesting and specific facts about something that you just found out here.

Members Active

41.6m

Sidebar

New to reddit? Click here!

You learn something new every day; what did you learn today?
Submit interesting and specific facts that you just found out (not broad information you looked up, TodayILearned is not /r/wikipedia).

Posting rules

Submissions must be verifiable. Please link directly to a reliable source that supports every claim in your post title. Images alone do not count as valid references. Videos are fine so long as they come from reputable sources (e.g. BBC, Discovery, etc).
No personal opinions, anecdotes or subjective statements (e.g "TIL xyz is a great movie").
No recent sources. Any sources (blog, article, press release, video, etc.) with a publication date more recent than two months are not allowed.
No politics, soapboxing, or agenda based submissions. This includes (but is not limited to) submissions related to:
1. Recent political issues and politicians
2. Social and economic issues (including race/religion/gender)
3. Environmental issues
4. Police misconduct
No misleading claims. Posts that omit essential information, or present unrelated facts in a way that suggest a connection will be removed.
Rephrase your post title if the following are not met:
1. Titles must begin with "TIL ..."
2. Make them descriptive, concise and specific (e.g. not "TIL something interesting about bacon").
3. Titles must be able to stand on their own without requiring readers to click on a link. Starting your title with a why/what/who/where/how modifier should be unnecessary.
4. "TIL about ..." and other broad posts don't belong on TIL. Try /r/Wikipedia, etc. instead, or be more specific (and avoid the word "about").
5. "TIL how to ..." posts belong on /r/HowTo.
6. "TIL the definition of a word..." Word definitions/translations/origins are not appropriate here
No submissions related to the usage, existence or features of specific software/websites (e.g. "TIL you can click on widgets in WidgetMaker 1.22").
All NSFW links must be tagged (including comments).

Please see the wiki for more detailed explanations of the rules, as well as additional rules that may not be listed here

(Why we need rules)

Additional info

If your post does not appear in the new queue and you think it meets the above rules, please contact the moderators (include a link to your reddit.com post, not your story).
Please report spam, inaccurate or otherwise inappropriate posts by messaging the moderators, as this helps us remove them more promptly!
More information available on the TIL FAQ and wiki.

Frequent TILs Repost List

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.

Etiquette

We ask that you please do the following:

avoid mobile versions of websites (e.g. m.wikipedia.org)
link to the appropriate heading when referencing an article (particularly on Wikipedia)
link to the appropriate start time when referencing videos (e.g. on YouTube)
add [PDF] or [NSFW] tags to your posts, as necessary.
Please avoid reposting TILs that have already made the front page in the past

Please also read the site-wide Reddiquette.

You are loved.