I, previously, was convinced that the song "Lucy in the Sky with Diamonds" by the Beatles was something totally different. I used to be a big fan of Charlie Brown (ha!) and thought it was "Lucy's in a fight with Linus". AM I AN IDIOT OR WHAT?? I thought this was funny because those characters do fight a lot. Go figure.
A childhood belief about misheard lyrics

others believed things like this
- I thought that the line was "Lucy in the Sky with Linus" (not lucy in the sky with diamonds)— Forrest
- i used to believe that in the i love lucy days, everything really was in black and white— allison
- I used to believe that the heart at the beginning of the I Love Lucy Show was made of real chocolate.— Krissa
- I used to believe that everytime i saw a helicopter the A-team were in it on their way to fight the baddies!— Natalie
- i used to believe that if i wasn't nice to my toys, they would fight back.
Anon - I used to think an Afghan hound was a breed of terrorist dog that had to fight in the Taliban!Anon