My mother used to tell me that there was another world called the dopple-ganger world which was exactly the same as this world with people doing exactly the same things as we did on this world. There was another me and another mum on the dopple-ganger world having this exact conversation at this exact time.
She told me that the dopple-ganger world was the real world, and this world was just a simulation.
She also said that whenever we went on holidays the dopple-ganger gods got really angry because they had to do extra work making the simulation. (Normally they just had to simulate our house, school, the supermarket etc...)
I never really believed her, but I thought that was a pretty twisted thing for a mother to say to her daughter.
A childhood belief about imaginary friends

others believed things like this
- I thought the world was black and white because of all the smoke from the bombs in Second World War.— Bjoern
- Until a few years ago, I believed this was a "doggy dog" world, rather than a "dog-eat-dog" world.— jemima
- I used to think that the phrase "It's a dog eat dog world'' was its a dogey dog world.— Gabral
- I used to think a world record was a record of all the people in the world singing .— JACK REGAN . [SWEENEY . ]
- I used to believe that we lived inside of the world. I asked my Dad who lived on the outside of the world. — Pauline
- I used to think that world wars's were called war wars. So then World War II became War War II.— Maria