My pediatrician used to tell us that our belly buttons held our butts on. He said he had a whole box full of spare butts, so when a kid lost his belly button, he wouldn't have to go around without a butt.
A childhood belief about belly buttons

others believed things like this
- I used to believe your belly button was a knot that held you together - my parents had wierd anatomical views— anne
- I used to think that if i touched my belly button it would unfold and my belly would be inside out forever. Anon
- I used to believe that your belly button was what held your top half to your bottom half...— Debelouwho
- i used to believe that if you poked yerr belly button yerr butt would fall off.— jordy
- i uses to believe that boys wee'd out of their belly buttons.— boys and toilets
- I used to believe that babies came out of belly buttons — kels