When I was little, my parents referred to round, spherical poops as "balls" - so of course, whenever boys referred to their "balls", I thought they were talking about their bowel movements. At school, a girl dared a boy to shout "MY BALLS ARE BIG!!!" I remember thinking, "hmm, that's not such an embarassing dare."
A childhood belief about rude bits

others believed things like this
- I used to think that girls had "balls" and not boys, and the "balls" were slang for breastsAnon
- i always thought it was Grape Balls of Fire instead of Great Balls of Fire— Courtney
- I remember once a friend of mine told me that when ever you hold in your pee it would make your balls stronger— Zao
- I also thought that meat balls were made from testicals— Glenn
- I originally thought "balls" was slang for buttocks instead of testicles.Anon
- I thought planes collected clouds to make cotton balls.— Eddie