I asked my older sister what a thong was and she said
"undies that go up your butt"
SO I imagined that it was underware with a pole on it that you would stick up your asshole.
Believed this one until high school when thongs got popular: why the heck would people WANT to stick poles up their butt?
A childhood belief about rude bits

others believed things like this
- When i was young i thought a stick shift was when u drive with a stickAnon
- I used to think you had to stick those pins that you stick in your hat through your scalp. That's weird.— Angela
- My friend used to think hit me with your rythm stick was hit me with your fiddle stick!! lolAnon
- I used to think that the b-word was buttAnon
- I used to think that babies came out of the butt— Claire
- I was always told that if you swollowed chewing gum your Bum would stick together.— Missa