I used to (ok, the habit stuck, I still do) stick my finger in my belly button. My parents told me that if I took my finger out, all the air would come out. I was terrified that I would die if "all the air came out."
A childhood belief about belly buttons

others believed things like this
- I used to believe that If I stuck my finger really far inside of my belly button I could touch my insides.Anon
- I used to believe that a half moon was gods finger nail, and his finger was pointing downwards.— clo
- my brother (10) still believes that if you stick your finger to far up your nose you can touch your brainAnon
- My mom told me that if I picked my nose, my finger would stay there someday!!— baxter
- my grandpa told me if you pick your nose too far then a snail will bite your finger off haAnon
- I used to believe your belly button was a knot that held you together - my parents had wierd anatomical views— anne