When I was young (around 5 or so), I was convinced that the movie "Milo and Otis" was called "My Little Otis". I called it that for a few years until my parents decided to break it to me I was saying it wrong.
A childhood belief about films

others believed things like this
- Until I was about four and a bit my father had me convinced that Friesian cows were called "big cats".— Chris
- When I first started learning to read I was convinced that vowels were called barnacles.— Andy Howell
- My mother's name was Anna. She was called "Annemor"(Duck mama). I was convinced I was a duckling.— Christine Norway
- I believed that the breed of dog called Boxer was called that because they could stand up and box.Anon
- I used to believe that all parents were called "Inge and Dirk", just like mine— eva
- I always thought when I was a kid that Milo is for boys and that milk are for girls. . . — Cathyia