When I was little, I used to think that the nine planets, Mercury, Venus, Earth, Mars, etc., were all located inside the "world", which looked like our globe. So North America was "Earth", and each of the other continents was also a planet. It never occurred to me that there weren't nine continents. And I thought "space" was the area between the planets inside the world, and outside the world was "outer space." It wasn't untill later that I figured out that Earth and the World were the same thing.
A childhood belief about outer space

others believed things like this
- I used to believe that there was only one lighthouse in the world and it was at the centre of the earth. Anon
- The very first time I saw a globe (of Earth, yes) I asked where "College" was located.— Shade
- I used to believe that the world, Earth, was enclosed in glass, like one of those snow globes.— G
- I used to believe that human lived inside the planet earth and not on its surface.— Giancarlo
- I used to think that planet earth was the only thing that existed in the universe— Santiago
- I used to believe that we lived inside of the world. I asked my Dad who lived on the outside of the world. — Pauline