I thought that when a woman went for her check-up, they put her to sleep (general anesthesia), because who'd want to be awake when some doctor-man is looking at your private parts?
A childhood belief about rude bits

others believed things like this
I used to believe a man and a woman needed a doctor to put their parts together when they did it.— Phil- I thought there were only four ranks in the army: private, corporal, Seargeant, and General— Alberto Richardson
- When I was a child, I used to believe that armpits were private parts— Duda Gueiros
- I thought a major general is more powerful than just a general (which still kind of makes sense to me)— Demond
- I, to this day, believe that when I can't sleep at night it means I'm awake in someone else's dreams... — Turner
- I thought when Grandma's hens were cackling, they were giggling about some private joke in the henhouse. — Not a farm kid