This one sounds a bit grim, but is still funny: I used to believe that when someone died in a hospital, the coffin was kept under the floor or behind the wall, so when the life support machine went off and they died, the body would go through the machine and into the coffin, ready for the funeral.
A childhood belief about people

others believed things like this
- When i went to a funeral only a bit of the coffin was open so i thought when u died you turned into a migit.— Andrew
- I used to think that when you died, you would be awake trapped in your coffin rotting for all eternity!— Trapped in the Coffin
- When my favorite Uncle died, I thought if I stared at him in his coffin he would open his eyes and be alive.— Cindy
- i used to believe that our ansering machine was the washing machine and that it could talk
— tamara - I thought there was some video games so hard that if you died on them you also died in real life!— Kakuri
- When I was little I believed when an actor died in a movie, he died in real life.— Ben