For the longest time when I was a kid, I used to think the lyrics to the Bob Dylan/Eric Clapton song "Knockin' on Heavens Door", was:
Knock, knock, knocking on Evan's door
Knock, knock, knocking on Evan's door
Knock, knock, knocking on Evan's door
Knock, knock, knocking on Evan's door
..... Feel like I'm knockin' on Evan's door...
I could never figure out who this guy "Evan" was, and why he would never answer his door!
A childhood belief about misheard lyrics

others believed things like this
- My sibs and I thought that the screen door was called the "scream door" so Mom could yell at us through it. — Kyle
- I used to believe there was a secret door to the gremlin world hidden under my bed— Mel
- i thought there was a door in the back of the tv and if you wanted to be on tv you just walk in— fred
- My friend desided in kindergarden that she would be a door when she grew up.— Oops!
- I used to think that you could get a tan if you turned the oven on, opened the door and stood in front of it.Anon
- i used 2 believe when i left my closet door open at
night a skelleton would pop out and wave at me— bex