I thought there were ten planets, with the sun as the first planet, Mercury as the second planet, and so on up to Pluto as the tenth planet. This was because I had a picture dictionary where one of the pages was of the solar system, and it listed the sun first, and then the nine planets. (This was before Pluto was demoted to dwarf planet.)
A childhood belief about outer space

others believed things like this
- I used to think God was Captain Planet.Anon
- I used to think each country was it's own planet.— erin clements
- i used to believe that spain was on a different planet
— shannon cannan - i used to believe that every country was a different planet!— bianca
- When I was young whenever I rode on an airplane I always thought we were traveling to another planet. — Dennis Rueda
- I used to believe that the United States were a planet, since I'm from another country.Anon