Skip to content
Search AI Powered

Latest Stories

Outdated 'Facts' People Were Actually Taught In School

Reddit user BiAdventureTime asked: 'What’s an outdated “fact” that you were taught in school that has since been disproven?'

Make us preferred on Google

If you went to elementary school around the same time I did, you learned that there are nine planets in the solar system. Then, in 2006, it was decided Pluto did not fit the bill when it came to requirements for being a planet.

Suddenly, there were no longer nine planets in the solar system. There were only eight.

The solar system having nine planets is an outdated fact, since it used to be fact, but is no longer true. This happens quite often.

We learn something, accept it as fact, and then its disproven and becomes outdated.

A lot of what we learn in school are considered outdated facts. We learn a lot of things that aren't true, or were true at one point, but aren't anymore. Redditors know this all to well and are eager to share their stories.


It all started when Redditor BiAdventureTime asked:

"What’s an outdated “fact” that you were taught in school that has since been disproven?"

The Perfect Diet

"The food pyramid"

– Froticlias

"I have a clear memory of a grade school health teacher telling us that we were only supposed to have 1 gram of fat per day. She held up a packet of 2 Reese's Peanut Butter Cups which has like 5 grams of fat in it, and we asked if we'd have to have 0 grams of fat for five days in order to have that, or just eat a sliver of one peanut butter cup."

"Super bogus stuff. I know it's not healthy to eat peanut butter cups all day, but your brain needs fats to live."

– weenertron

Bird's Eye View

"You can see The Great Wall of China from space (ISS)"

– azazeLiSback

"This was always a weird one. The Great Wall of China is long but it's not that wide. If you could see it from space surely you'd be able to see roads and smallish buildings so it wouldn't be that impressive."

– AP246

"I didnt believe you. Googled it. You were right. This should be the top comment. That lie has been so ingrained into my brain. Wow."

– Boomshockalocka007

Crack, Crack

"Cracking your knuckles causes arthritis"

– MosesOnAcid

"This is a reminder that your knuckles are reloaded, feel free to crack them now."

– Crisis06

"I've always liked the story of Donald Unger, a doctor who cracked each knuckle on his left hand (but not his right) for 60 years to see if it contributed to arthritis (it didn't)."

"He won an Ig Nobel prize for it:"

– JinimyCritic

Before Smartphones

"You won't always have a calculator in your pocket"

– bread_makes_u_fatt

"That's actually true. Sometimes it's in my hands"

– dfreshcia

Bitter, Salty, Sour, Sweet, Savory

"Tastebud zones on the tongue."

– GrilledStuffedDragon

"I argued with my science teacher in 4th grade about this. Even to a 9/10 year old, this made no sense. She went to cafeteria and got some salt packets and sugar packets. We did a blind taste testing experiment. In the end, she had us draw an X through the picture in our science books. I have SOOOO much respect for teachers that can admit they are wrong. All people really, but especially teachers"

– whovian5690

Revolution!

"I was taught that Mercury was the hottest planet. A student corrected them on a national level and they changed how it was taught."

– KaJashey

Just Say No

"They told us that smoking one “marijuana cigarette” was equivalent to smoking 20 cigarettes and was 10X more carcinogenic."

– Jeramy_Jones

"We were also told that if we tried weed, we'd also want to try other drugs."

– Sadimal

"This is a hot frying pan. This is an egg. This is your brain on drugs.. sizzle, sizzle, sizzle."

"Holy crap, I was immediately convinced. /s"

– MsMisty888

Centimeters, Not Inches

"The US will be using the metric system in 10 years."

– Merrybee16

"I can remember being in 2nd grade, and one day the teacher stopped class for us to listen to the principal read this very serious speech over the PA system announcing that the metric system was coming. For some reason we all thought it was changing that day, and that there was a test after. Seriously, some kids cried. This was in the 70’s…lol."

– Speakinmymind96

"The reality is that the US will be using the metric system in 12 and 5/8 years."

– ClownfishSoup

Blue Bloods

"Blood is blue in your veins, but turns red when it hits oxygen. Idk if it was really a fact then or been disproven but I've learned it's not true."

"8th grade health class teacher taught us that."

– ninreznorgirl2

"Such a weird myth. It seemed fishy to me even when the teacher was telling us this is in second grade."

"Seems like a logical leap someone made because they looked at their arm and saw blue veins"

– mothwhimsy

"Our veins are blue simply because of the light spectrum."

"I can't remember the exact reasons, but it's something to do with blue being one of the colours that isn't filtered by our skin as well."

– Drakeskulled_Reaper

"This is one my mom told me my whole childhod and I didn't question. I believed it until as late as the 9th grade. There, in basic biology class, my teacher stated like it was sooo obvious that everyone knew blue blood was just a myth, and she was like "Nobody here thought that right?" I didn't raise my hand. I just stayed silent."

– RamenTheory

Cause and Effect

"Growing up, I was literally led to believe (and definitely not the only Black person), that Eli Whitney, inventor of the cotton gin, was Black."

– yhpargotohpts

"Not to mention, his invention of the cotton gin reinvigorated the cotton industry, which in turn reinvigorated slavery, which was starting to fade a bit because the labor of cotton wasn't worth it. With the cotton gin, they could process a lot more cotton, and slavery became worth it financially again."

– VillageSmithyCellar

"I was taught this as well. The Cotton Gin helped rid the US of slaves because they no longer needed to pick out those pesky seeds by hand."

"Nope. Made slavery more profitable. Larger profit margins = more slaves."

– Hoopajoops

Hand Me The Screwdriver

"The difference between man and animals is that animals don’t use tools."

"Myth busted."

– tikivic

"Chimpanzees have entered the chat. And capuchin monkeys. And crows. And octopus. And sea otters. And..."

– Agreeable-Damage9119

20/20

"Carrots help vision. "

– waconaty4eva

"Carrots do technically have some things on that your eyes need. But they do not improve your vision. I believe it was a rumour started by Britain so the Germans didn't realise we had radar."

– Donut_Klutzy

Rarely True

"I before e except after c"

– Horrorbmoviepunk

"Unless your feisty beige foreign neighbor invites you on a heist."

"Edit, missed one......invites you on a sleigh heist."

– NetDork

"…except sounding like “a” as in “neighbor” or “weigh,” except for eight exceptions including weird."

– spiderwebs86

Steer Correctly

"I was taught that you put your hands on the steering wheel at 10 and 2. My teen daughter learned this summer to put her hands at 9 and 3 in Drivers Ed. Apparently it’s safer if/when air bags are deployed."

– TraaashTVaddict

"A lot of drivers education programs are starting to teach 8 and 4 now."

– AgentOOX

"Can't wait until they finally get to my preferred "one on six, the other f**king with my radio.""

– Dogstile

The world is always evolving and changing, so education must too.

Are there any "facts" you'd like to debunk? Let us know in the comments below!

More from Trending/best-of-reddit

Donald Trump
Mandel Ngan/AFP via Getty Images

Trump Unveils Photo Of 'Newly Revamped' West Wing Entrance Makeover—And Critics Have Some Thoughts

President Donald Trump was criticized after sharing a picture of the latest update to the entrance of the White House West Wing that made the historic landmark look more like a signature Trump hotel.

The Oval Office has been significantly revamped since Trump took office in January 2025—it features, among other things, a fireplace adorned with gold cherubs and medallions, surrounded by portraits of American statesmen in ornate gold frames and shelves filled with gilded figurines, urns, and freshly installed Rococo mirrors.

Keep ReadingShow less
Nicolle Wallace; Marco Rubio and Donald Trump
MS NOW; Jakub Porzycki/NurPhoto via Getty Images

Nicolle Wallace Offers Hilariously Brutal Suggestion For 'Addled' Trump Amid 'Bizarre' NATO Press Conferences

MAGA Republican President Donald Trump has been participating in the NATO Summit in Ankara, Turkey, since Tuesday afternoon, but the visit has been anything but successful for the embattled POTUS.

Trump's appearances before the international press on hand for the summit have been rife with gaffes that have the domestic and international communities both amused and concerned over the 80-year-old's continued cognitive decline.

Keep ReadingShow less
Fashionista Rihanna attends the 2026 Met Gala, celebrating "Costume Art" at the Metropolitan Museum of Art.
Taylor Hill/Getty Images

Rihanna Applauded For Powerful Response To Cancer Patient Who Apologized For Looking 'Terrible' Without Wig

Rihanna’s latest viral moment has nothing to do with music, fashion, or beauty launches. Instead, fans say the singer helped someone shine bright “like a diamond” after reassuring a cancer patient who apologized for not wearing a wig during an unexpected meeting.

The nine-time Grammy winner, 38, made a fan’s day during a recent trip to a supermarket, where she posed for a photo and offered words of encouragement after learning the woman was living with cancer and feeling self-conscious about her appearance. The interaction appeared in Jason Lee’s video series, Jason Lee Unlocked: Grocery Shopping with Rihanna, released on Monday, July 6.

Keep ReadingShow less
Catherine Zeta-Jones; Bonnie Tyler
Monica Schipper/Getty Images; Christian Augustin/Getty Images

Catherine Zeta-Jones Pens Touching Tribute To Singer Bonnie Tyler After Death—And Fans Are Emotional

Bonnie Tyler, singer of "Total Eclipse of the Heart" and "Holding Out for a Hero," died on July 8, 2026, just a month after her 78th birthday.

She was in a hospital in Portugal, and she died unexpectedly from the illness she was being treated for.

Keep ReadingShow less
Screenshot of Rasmus Svaneborg; Mark Rutte
@atrupar/X; Altan Gocher / Hans Lucas / AFP via Getty Images

Reporter Puts NATO Secretary General On The Spot With Brutal 'Self-Respect' Question About Trump

NATO Secretary General Mark Rutte found himself on the spot after Danish reporter Rasmus Svaneborg questioned whether sitting silently beside President Donald Trump as he discusses "conquering" Greenland and criticizing allies has impacted his "self-respect."

Rutte, a former Dutch prime minister, has been forced to manage Trump's repeated criticism of NATO while contending with his public insistence that the United States should acquire Greenland from Denmark.

Keep ReadingShow less