I thought clouds were made of this http://www.hippeshops.nl/wp-content/uploads/2011/07/suikerspin.gif . I don't know how you call it in English. It's like candy on a stick.
I thought the monsters that would hide in the darkness/closet or under my bed were actually friendly and very shy, that's why i was never hurt by them or even noticed them. I even went to sleep in my closet once xD.
I grew up in kind of an old house, and they have "old house noises" if you know what I mean. I thought those were my friendly invisible monsters battling the bad evil monsters( and winning ofcourse).
My mother also told me once that I was confused that she'd be able to pick me up when I closed my eyes. How could she see me when I can't see her? Magic ofcourse. Which led me to believe that i was a wizard xD.
I was, and still am, confused when I touch myself: Do i feel my fingers touching my face or do i feel my face touching my fingers ?
I also learned to play the piano at quite a young age and i thought that when I played, i was actually putting the sounds in other people minds. I tried to find a way to use the piano to put thoughts into other peoples mind. And because my grandmother (who is the one who taught me), always gave me a bit of cash when she came over, i thought it was because I made her think she wanted to give me a bit of cash when she came over >
!.