When I was little I believed you got breasts when you got married! My belief was based on the fact that the only women I saw whith them were married, thankfully it's not true as I have them now and am not married yet!
A childhood belief about rude bits

others believed things like this
- when i was young i believed that gay men got married to gay women!— robster
- i used to believe nuns were married to jesus and priests were married to mary.— sunshine
- I used to believe that when you got married you immideatly got pregnant and so I was terrified to get married— leo
- I used to believe that women could only get pregnant once they were married and it just sort of happened Anon
- When I was younger I used to believe that women just magically got pregnant after getting married.Anon
- When I was younger, I believed that Priests could get married, but only to Nuns— MJF