When I was little, I believed there were secret passages in our ceiling, and if I could only find the opening, then I could sneak up in them after bedtime and see what my parents were watching on t.v. (which was far better than anything I was allowed to watch, I was positive).
I also believed that my cousin and I were aliens sent from another planet to live with a human family to "study their ways". We would be retrieved after sufficient data had been collected through our eyeballs (which were obviously cameras).
Still waiting on the last one.
But, while I wait, I have been vastly entertained by I Used To Believe, a website where we adults can confess all those silly childhood beliefs.
I love the internet.