I thought that the universe was in the shape of a pyramid and our solar system was somewhere on the south side of it (yes I know there's no south in space but I didn't as a kid!)
A childhood belief about physics

others believed things like this
- when I was small I always thought that the solar system ended, and then it was just white paper after that— sparrow
- i used to believe that all of south america was mexico— katie
- i used to believe that hawaii was located right south of florida. hey, they both have great weather!— ashley
- I used to believe that north was always straight ahead. I could never face south, but I knew it was behind me!— Bruces
- I used to believe that clouds were made from a factory chimney that was south of my home town. — bynbyn
- I once believed that one could run around the south pole in order to travel backwards and forwards in time.— kaibutsu