I couldn't understand why after putting a piece of coal next to a hot furnace wouldn't turn it into a diamond. Forgot it also needed pressure.
A childhood belief about physics

others believed things like this
- I used to believe that the heat from the furnace came from hell, and that it was a straight drop there.Anon
- i used to believe that coal from stockings was santa's poop because i was bad— dylan mcdonald
- I used to think that neil diamond was singing about the reverend blue jeansAnon
- I used to think that boysenberry was poisonberry and couldn't understand whay anyone would want to eat it.Anon
- I could NOT understand why, if a pen worked on paper, it couldn't also write in thin air.— Can you guess what it is yet?
- When I was little, I couldn't understand why people called me a tomBOY, instead of a tomGIRL.— Amanda