I used to believe a fart was when air got trapped in your underwear and made a noise squeezing out of the elastic in your underwear's leg holes.
A childhood belief about farting

others believed things like this
- I used to believe that "utensils" were underwear!— Haley
- i used to think the song "walking in a winter wonderland" was "walking in a womens underwear"— stephen s
- I used to believe that baby oil came from squeezing babies— Angelina
- my gran tod me that rabbits made a noise that went "map map"— Lise
- I used to believe that my grandpa had a special power that made him fart each time I pulled his finger. — confused
- I used to think that the wind that made a howling noise was a ghost.— Febi