Not me, but a bunch of my friends! We were on a class trip to the aquarium, I was six (or maybe five and a half) and at least four but maybe even the whole class of my friends wanted to literally "find Nemo" as in the movie Finding Nemo, in the aquarium. They thought Nemo was in there, but I knew even then that he was a cartoon character and he was in the sea. At one point, a boy found a clownfish he thought was Nemo, but another boy said, "No, you fool! Marlin!" (Marlin is Nemo's dad).
A childhood belief about films

others believed things like this
- I used to believe that the Chinese boy in my kindergarten class flew from China every day to get to class.— Debi
- I remember a girl in my kindergarten class told me she wanted to be a waterfall when she grew up.Anon
- I thought Hurricane Dennis (in 2005) and the character Dennis from the Spongebob movie were related somehow.Anon
- One of my friends told me that when he was a kid he thought windmills were used to keep cows cool!— Julie
- I used to think my elementary school gym teacher's name was "Jim Class".— Brandon Campbell
- One of my friends in elementary school thought that Osama bin Laden was "a son of Aladdin". Anon