I remember once my mom was explianing periods to me. She told me that when I had my period, I couldn't go near water. Wide-eyed, I asked, "I can't even drink water?" I thought that for a while.
A childhood belief about periods

others believed things like this
- My mum used to tell me that you couldn't drink water out of the tap from the bathroom as it was poisonous.Anon
- I thought tonic water was toxic water and wondered why would anyone drink it if it is toxic?— Dr.Badguy
- When I was young I refused to drink well water because I thought it came out of whales.— itodd
- I thought that hydrogen was pure water (since I knew hydro- meant water) and H2O was impure some how— Hexetic
- My Sister Used To Believe She Could Fly By Driniking Water From A Magic Forton. I Told She Couldn't.— Zoe
- I used to think that if I ate a fruit seed it would grow in my stomach if I drink water after thatAnon