This is not my belief, but a boy at my school told me he hadn't found out that girls have nipples until only a couple of years a ago (he was about 14?). He thought only men had nipples, not women. I wonder how he couldn't have known!? And for so long!
A childhood belief about general

others believed things like this
- I thought nipples disappeared at a certain age because Barbie never had them.Anon
- When I was younger I thought I had made up the word "nipples" and "thinga-majigger" — Amelia
- I used to believe that ants had the smallest nipples in the worldAnon
- I used to believe that all my energy "came from my nipples and my back" I literally said that to my parents.— Eleanor R
- I used to belief that women had babies by pressing their belly buttons!— amy
- My Mum told me if I ate too much toast I would get cancer! I couldn't eat it for years and years...— Pauliboy