My mother told me that when I was three or four I used to believe I had babies.
Let me explain. I had a dozen babies and apparently I could make them jump in and out of my stomach when they needed to hide or I was going somewhere.
My mother said she went to sit down beside me one day and I yelled, "NO! You'll crush my babies." I then proceeded to call them all by name and wouldn't let her sit down until they had all jumped in.
I have no recollection of this but...Wow!
A childhood belief about imaginary friends

others believed things like this
- When I was young my mother told me that old people kind of shrink. I thought that they shrunk into babies.— dont know
- I used to believe that babies were born out our bellybuttons.Anon
- I used to think when you married you had babies immediately!Anon
- I used to think that bidets were for washing babies!— Helen
- when i was little i used to belive that barbies could have babies!!!!!— kay~gr.7
- I used to believe that midgets were just really smart babies — Nightmare