When my niece was little, about 8 years old, I had her convinced that twins (I have an identical twin sister) did not have belly buttons. It took her about 5 years to learn the difference. I am a little bit over weight, and I had pulled the front of my pants down just far enough to where you would think a belly button should be.
A childhood belief about belly buttons

others believed things like this
- i used to believe that guys pulled out their outie belly buttons and that's how they peed.— Sky
- I used to think that if i touched my belly button it would unfold and my belly would be inside out forever. Anon
- My younger sister used to believe that in everybody's belly button there lived a family of squirrels.— Sophie
- 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
- that bunnies came out of belly buttonsAnon