Pieces of 'Common Knowledge' That Are Actually Totally False

There are pieces of knowledge that we just pick up from our everyday lives. No one necessarily sat us down and told us we eat eight spiders a year in our sleep, but it's just one of those things you hear and sounds plausible enough, so you believe it and spread the fact. Problem is a lot of "facts" like that aren't actually true. In this AskReddit thread, people shared the most common pieces of knowledge that are actually total fabrications. Some of them might shock you!

I think we all forget sometimes that bombs don't actually create "flaming bursts of fire." Luckyboy28 explains that "those are gasoline explosions that look good on camera, so they're used in movies. But when an actual bomb goes off, there's usually no fire, "just concussive force and shrapnel."

Psychological_Ride explains that dogs don't see in black and white like we were told. And it's true! I went to a museum exhibit about dogs and there was a viewfinder that simulated a dog's vision. They see colors, but they see fewer colors and their vision is much blurrier than ours.

Contrary to popular belief, explains Evan-UgLee, ostriches don't stick their heads in the sand because they're scared. They do it to look for food. 

Haven't you always heard that you should never wake a sleepwalker? Well, that's a myth, according to OwnMathematician7. A doctor chimed in on this thread to say that they usually give that recommendation for children who sleepwalk because they can become disoriented and very uncomfortable. But it won't cause a heart attack or anything.

Growing up, I always heard that whatever hair you shave comes back thicker than before. Of course, that's a myth, as ZanyDelaney points out. One commenter brought up a good point: "If this were true, all balding men would shave their heads over and over until the hair was so thick they could let it grow."

I was always told that most of your body heat escapes through your head and your feet, but according to AmeglianMinorCow, that's not true. It's actually closer to about seven percent of your body heat, "which just so happens to be the same percentage of your body that the top of your head occupies."

People still insist on tilting their heads back when they get nosebleeds, but don't do that! Juuluwuul points out that you're actually supposed to lean forward when you have a nosebleed and pinch your nostrils together, not the area with bone and cartilage.

Megablzkn explains what's wrong with the idea that "If you touch a baby bird, the mom bird will smell you and abandon the baby." They write that most birds actually have a poor sense of smell. But they have great eyesight. So it's not your smell but your actual proximity that will keep mama birds away until they deem it safe to return to their babies. 

Hey! Our blood isn't blue until it hits oxygen. That's absurd, even though it's something we all believed at one point! ROADHOG_IS_MY_WAIFU explains that it's only blue on anatomy charts in order to tell which way it's flowing. And someone else tells us that it only appears like our veins are blue because "that end of the spectrum of visible light has better penetration through your skin."

There have been whole movies based on the idea that humans only use 10 to 15 percent of our brains, but according to yoyosarefun123, that is "wrong to the core." It's not just 90 percent mush up there... for most people, anyway. 

Somehow, it became well-known that you can't report a person missing until after 24 hours, but as BlueRose104 points out, that is completely wrong. If someone is missing and it's been a concerning amount of time, no matter what that length of time is (within reason), please report it!

We don't swallow eight spiders a year! What good news from Dame_Mort. Someone else confirms that we do not normally swallow any spiders in a calendar year, so that should put some of your spooky nightmares to rest. 

So much is made of Napoleon Bonaparte's height, but he wasn't actually as short as the history books make him seem. According to Alexeidh, "he was around 5'6" or 5'7" which was actually above average for Frenchmen of the time."

We were all told not to go swimming for at least half an hour after eating, but there's no actual health reason for that, as smalltownlassie explains. Likely, the myth was started by parents who wanted to sit and enjoy their lunch and weren't ready to monitor their kids in the pool. 

Every mother in the world has warned their kids not to go outside without a coat on because that will make them catch a cold. However, that is 100 percent bogus. Canadaehbahd explains that one of the reasons colds tend to spread during the colder months is because people avoid going outside and are inside breathing on each other and spreading more germs than they normally would.

Many people blame cow farts for many of the harmful greenhouse gas emissions, but leyoonsky points out that it's not cow farts but cow burps. Well, excuse them.

Too many people think that urine is sterile. It is not, as vote_for_asteroid points out. This is outdated information and so wrong and please, please don't drink your urine.

There is a pervasive myth that carrots improve your eyesight or can even make you see better in the dark, but this is totally wrong, as Hamsternoir writes. Carrots contain vitamins that can help fortify your eyesight, sure, but they won't help you get back vision that you already lost or give you night vision abilities. Sorry.

I'm sure we've all been asked, "Are you more left brain or right brain?" Supposedly, the left side of the brain is used for logical thinking whereas the right brain is used for creative and emotional thinking. But there's no actual way to measure this, says stonerkid10. While it's true that each hemisphere is responsible for certain processes, there's no way to tell if you are "more" right brain or left brain. 

People get crazy about hand sanitizer during flu season, but here's the problem, according to swanish365: Hand sanitizer only kills bacteria. The flu is a virus! Please don't rely on hand sanitzer to keep you from getting the flu. Wash your hands, and get your flu shot!