What's something you were told so you would listen/behave that made no sense or you laugh at now?

My family told my younger sister that dark soda would turn her stomach to plastic and she avoided it for half her life

We always tell the children in our family that the "señor" will get them if they are out of line. We don't even say why, we just suggest they will be snatched. Sometimes my family would point to a random person while we were out and say 'that señor is going to get you. Behave" - the poor men, if they only knew

I used to love the Rugrats when I was young, and there was an episode where Chuckie ate a watermelon seed and it grew inside of his stomach (or something to this effect), and my aunt told me that it actually happens. I thought it was true until I was a teenager I still don't eat it.

I remember that one My sister claims she still thinks twice about doing things because of my parents

A warning is that I should never swallow gum or else I'll turn into this:

If I stepped on a crack I broke my momma's back

If I held my nose when I sneezed, I'd blow my brains out

If my parents had said that, I think I would've been traumatized as a kid

This

I also heard if you sneeze with your eyes open, they will pop out of their sockets. But I think this might actually be true

I'm pretty sure it's impossible to sneeze with your eyes open hihi

This one is TMI but Ima try to keep it cute:

My stepdad told me that if I didn't wipe properly/at all worms would crawl up my no no hole.

Yes but if you could, your eyes would pop out hihi

Oh my god

Wiping is essential, don't forget hennies

I still think about this but with pumpkin seeds. I was so scared cause I ate one once in a piece of roasted pumpkin.

I came here to say this.

Oh my god some of these are wild
I have never been warned like this, what is wrong with the people that told you these stuff

The daycare employees told me eating playdough would cause leeches to develop inside my body

I was told something similar!

My sister mentioned in the OP and me were talking about the soda thing and she was fuming. She only drank Sprite for years Now she's only into coke