When we were ten, my class learned about sex (just the basic stuff like eggs and sperm, nothing that would traumatise us too much at that point).
Anyway it that class had a best guy friend who acted real girly and hung out with us girls more than he hung out with guys.
In my class was also this kid who assumed that if a boy wasn't manly and was too girly, he had eggs instead of sperm.
So, yeah, one day, he told my best friend that he had sperm instead of eggs, in front of the whole class, teacher included.
A childhood belief about reproduction

others believed things like this
- When I was a kid, I used to believe that cadbury cream eggs real uncooked eggs in the middle Anon
- I thought sperm were fish and when I got a goldfish I went around telling everyone i had a sperm— Kara
- I used to believe that the Chinese boy in my kindergarten class flew from China every day to get to class.— Debi
- I used to believe that only brown eggs came from chickens. I thought white eggs were made at the store— Destiny
- a friend of mine thought that you could get pregnant by swallowing sperm. Ha!Anon
- I used to think my elementary school gym teacher's name was "Jim Class".— Brandon Campbell