In the song Rudolph the Red-Nosed Reindeer there is a line that goes "As they shouted out with glee". When my mom was little she used to sing "As they shouted out with Gleem". Gleem was a toothpaste brand back then. We still sing it this way just to tease her.
A childhood belief about misheard lyrics

others believed things like this
- For the longest time I thought that Rudolph the Red-Nosed Reindeer had a very "chinese" nose...Anon
- i used to bielieve if you get hit
in the nose you will turn into
rudolph the rednose reindeer— kurt santana - Did anyone else sing "Hark, the hairy angels sing"?— Jill
- My mum said that when I used to sing "noahs arc" at school I would sing "who built the arc, no one, no one"— Clare
- I thought that singer/songwriter was spelled this way: sing-a-song-writer...Anon
- in the song "show me heaven" i used to sing "make me breakfast" instead of "leave me breathless"Anon