I used to believe... if you were a teenager and got a tampon wet by placing it under a running faucet (in the bathroom specifically), it would start bleeding.
A childhood belief about periods

others believed things like this
- I used to believe that some first names were specifically for children and some were specifically for adults.— Marco
- I used to believe that I could fly like Superman if I had the right cape and got a good running start. — Rick
- I used to think running for president involved actually running somewhere.— Artimage
- in kindergarden i beleived that to be a teenager your name had to end with teen— eric
- When I was a teenager, I used to believe that someone's name-day occured as half-birthday.— Marcas
- I thought your loins were kidneys, and nobody corrected me until I was a teenagerAnon