When I was young I used to believe that saying "excuse me" after passing gas made the smell go away so I would say it repeatedly after farting with the hope that no one would smell it before the words made it go away.
A childhood belief about farting

others believed things like this
- I used to believe that hairspray was made of grapes! =) Does't it smell grapey to you? XD— Jaime
- I used to believe that when I farted, i could smell up all the stench before anyone else could smell it.— Tim
- I used to believe that I could smell when it was going to snow.
(I still can!)— sw - Skunks smell bad because they eat garbage.— Isabel
- I used to believe that if you swallowed your gum that you would crumble up and smell like a dead animal !!!!— jordan
- I used to think I had the special power of being able to smell things with my finger.— Pablo