Not mine, but the little brother of a friend.
We were playing with our dolls at the time, and one of the kids had somehow got a hold of a box of tampons and filled the back of a toy car with them.
Upon discovery, my friend's youger sister asks "What are those for?". Her brother answers enthusiastically, "You're meant to eat them!".
We spent an awkward few minutes convincing him not to do it.
A childhood belief about periods

others believed things like this
- I remember once a friend of mine told me that when ever you hold in your pee it would make your balls stronger— Zao
- My friend's sister believed the lyrics to Gazza's "Fog on the Tyne" were "Fog on the dinasaurs mine all mine"— Suzanne
- I used to believe that if I cut my dolls hair it would grow back just like mine did after a haircut. — diamond girl
- When I was younger, I think i can change my brother with a friend— Mbaclé du 55
- once me and my friend stuck her mums tampons up are butts thinking that you didnt have to poo— ha ha ha ha
- My friend's mom told my friend's little sister thatI when a dog died, it went to a retirement home.— ellen