As a small child, I used to believe that Elizabeth Taylor (the actress) and Queen Elizabeth (the queen) were the same person. I think I figured out the difference around 3rd-4th grade (1962), but I was really confused there for a while (both were in the news a lot back then).
A childhood belief about films

others believed things like this
- I used to believe that my mum was the queen. She does look a bit like the queen... minus the orb and sceptre.— Vix
- I used to believe that everyone had the same middle name as me... Elizabeth.
(even my uncles)— K.O. - I used to believe that if the queen died we would all die too. I think it had somthing to do with bees.— Darrell
- i used to believe that if i was good at school, i had a chance of becoming the queen????— donia
- I used to believe that Prince was the lead singer of Queen— Garrett
- When the Queen Mother died when I was quite upset because I thought royalty did not die.— Carrie