I used to believe that Newton's 3rd Law (for every action there is an equal and opposite reaction) could work both ways....the example we were given was that "if you push on a wall, the wall pushes back"....I used to walk down the hallways worriedly thinking "what if the wall pushes FIRST!!??"
A childhood belief about physics

others believed things like this
- I used to believe that at the end of the universe was a big plywood wall.— matt
- I used to believe that the cool aid man was evil and he'd break through my wall and get me.— tammy
- I use to believe that my grandpa invented the wall because his name was WallyAnon
- I had a little hole in the wall under my bed when I was little and I thought that Fraggles lived in there.....— Tina
- I used to think that Hadrian also built the Great Wall of China.— Spacey
- I used to think that The Great Wall of China was made out of porcelain.— Morten Vestergaard