I used to believe having sex would make your genitals explode/fall off.
A childhood belief about rude bits

others believed things like this
- When I was little, I thought that bug spray would make bugs explode and disappear. Anon
- If you swallowed chewing gum it would make a balloon inside you and your stomach would explodeAnon
- As a youngster, my older brother told me that polish sausage was really the bull's genitals. — Ross
- I used to believe that if you point at somebody you make holes in the air and the fairys fall over— Bob #1
- i used to think that biting my nails would make my fingers fall off! ;)— Cassandra
- I thought if you trip and fall down you fall at the speed of light!— Dietrich Corby