I thought until yesterday that the lyrics of the teenage mutant ninja turtles' s theme tune was-
Whan the Evil-Shredder-Of-Tax,
(rather than the evil shredder attacks)
I always thought it had some obscure political message.
A childhood belief about misheard lyrics

others believed things like this
- If someone broke into my house at night my ninja turtles would come to life to protect me.— blip
- I thought that heart attacks were actually "hard attacks". Anon
- When I was, like, three, i thought my cat was an evil sorcerer and would cast a spell on me. XD— Bobbet
- As a kid I thought dogs stupid but funny and that cats were evil demons. — Gemini
- I thought that "heck" was a less horrible version of hell for people who were only KIND OF evil.— Oizys
- i used to believe that bald people were evilAnon