I believed the urban legend that gum stayed in your stomach for 7 years if you swallowed it.
A childhood belief about chewing gum

others believed things like this
- I used to believe the spleen was an urban legend— Nikki
- my mother told me if i ever swallowed chewing gum i'd turn into a pig, i believed this for many years.— stuart hayward
- my mom made me believe that if i swallowed my chewing gum, it would form one big wad in my stomach.— mimi
- i used to believe that if i swallowed beens,,a tree would grow in my stomach :P— fatma
- i used to believe that if you swallowed gum, when you breathed in, your stomach would stick to your back— cope
- I thought that if I swallowed grapestones, a tree would grow out from my stomach. — Tone