An old wive’s tale is a belief or superstition that widely believed but generally understood to be untrue.

A lot of us have believed an old wive’s tale since childhood without even knowing how or why we heard it in the first place.

Here are 13 popular old wive’s tales and why we should probably all stop believing them.

1. Peeing on a jellyfish sting helps

Photo by Clint Patterson on Unsplash

This story has been passed around so often that it definitely feels like fact.

Instead of having someone pea on you, try soaking the area in seawater to rinse and remove the tentacles.

2. Don’t swim after eating

Photo by Erik Dungan on Unsplash

It turns out that the worst thing that can actually happen if you swim after eating is you might get a cramp — but you won’t drown.

Swim on, friends!

3. Carrying high means you’re having a girl

Photo by Anna Pritchard on Unsplash

People love to accost pregnant women with all kinds of unsolicited advice and information.

One of the most enduring pieces is that if you’re carrying high, it means you’re having a girl. Carrying low? It’s a boy.

But… it turns out this is untrue. OB/GYN Adina Holand Keller explains:

“When a woman is pregnant you can’t tell the sex of the baby based on how the woman is carrying the baby.

If a woman looks like she is carrying high or low, it is based on the size and position of the baby and the shape of her pelvis.”

So there ya go ladies!

4. Your eyes can get stuck if you cross them

Photo by Austin Pacheco on Unsplash

Doctor Stephen Kronwith says not to worry:

“Children cross their eyes for fun, but they can’t hold the position for long, and it’s not dangerous.

They’ll see double, but it won’t leave any permanent issues.”

How many times did you hear this one growing up?

5. Bulls hate the color red

Photo by Stephane YAICH on Unsplash

Just like cows, bulls are actually color-blind, and the retina of cattle lacks the receptor for red completely.

They can see yellowish-green and bluish-purple light.

Wondering what actually bothers the bull? The motion of the flag, not the color.

6. The five-second rule

Photo by Sarah Kilian on Unsplash

Dr. Arefa Cassobhoy says all food is contaminated when it hits the ground:

“Eating food that’s fallen to the ground does come with a risk of taking in bacteria known to cause food poisoning.

Research shows food will instantaneously pick up bacteria from the surface it lands on.”

Sorry, guys: the five-second rule is totally false.

7. Coffee stunts growth

Photo by Nathan Dumlao on Unsplash

If you’ve been worrying about this one, relax.

Johns Hopkins says that the amount of caffeine in a drink doesn’t interrupt a child’s growth patterns.

Coffee for everybody!

8. Humans only use 10% of their brains

Photo by jesse orrico on Unsplash

A few years ago, Psychology Learning and Teaching cited the idea that people only use 10% of their brains as one of the most common misconceptions.

9. Mayo makes food spoil faster

Photo by Sara Cervera on Unsplash

A lot of people think that food made with mayonnaise will spoil faster, but it turns out that mayo can help keep food from spoiling as long as the food is kept cold.