i used to think, for some reason, that you got your period when you were about 13, but finished them when your stopped being a teenager (about 20). i also knew you couldn't get pregnant once your periods had stopped... it never occured to me that my mum was 30 when she had me! luckily, my friend corrected my belief before too long!
A childhood belief about periods

others believed things like this
- When I was a teenager, I used to believe that someone's name-day occured as half-birthday.— Marcas
- a male friend of mine used to think that only women who had been pregnant had periods— oiman
- I thought your loins were kidneys, and nobody corrected me until I was a teenagerAnon
- i used to believe that condoms stopped a mans wee getting out while having sex.— a boy
- That the rivers stopped flowing at night!— Louise
- When I was little,I used to think the TV stopped when I went to bed. I figured it all faded to white.— Sharon