I used to believe that I was the only person who knew that fairy tales weren't real. I would move stuff around the house or steal random bits of nothing and bury it out back so that they'd think the Borrowers had taken it. I had imaginary imaginary friends.
A childhood belief about fairies

others believed things like this
- I used to have an imaginary friend named Mr. Nobody. He would protect me from my imaginary enemy, Bad Elmer.— Kdees
- I thought my imaginary friend was real and he imagined me
I hope he still believes I existAnon - when i was growing up i had two imaginary friends. One was named Jennifer, the other was named Onion.— Tessica
- I used to believe that if you weren't good, the Trix Rabbit would steal your yogurt.— Kyle
- I used to believe if I concentrated hard enough I could move stuff.
*sigh*
— Zog - my aunt used to have an imaginary friend who instead of having blood had 7-up in her veins.Anon