This isn't my belief, but rather my younger cousin's- we were all driving down to the beach, and my aunt was playing her Beatles CD on the way down. The song "I am the Walrus" came on- on the part where it said "Semolina Pilchard, climbing up the Eiffel Tower", my cousin thought he was singing, "Sitting on a cornflake, looking at the Eiffel Tower" The funnier part was, I didn't know any better either, so I totally believed her! I didn't find it out until today when I was listening to the song, and decided to look up the lyrics for this one part that sounded weird to me...
A childhood belief about misheard lyrics

others believed things like this
- when I was little my uncle told me he was part bear. I believed people could be part bear until I was twelve. — Audrey
- I used to wonder why they didn't fix the Leaning Tower Of Pisa. Weren't they embarrassed that it was crooked?— Bootlebat
- My cousin's mom told my cousin that pop makes you short. He probably believed it.— Molly
- i once believed that foil in the chocolates are part of what we should eat.— angela
- When I was a kid I always thought that a water tower was the robot from the TV show "Lost in Space".— sherryj
- When I was young, I believed that because my mother was born in New Mexico, that I was part Mexican.Anon