I've heard many rumors about people doing covers of songs and butchering the lyrics. Here are some I've come across:
The ever-so-popular "Excuse me while I kiss this guy" ("Excuse me while I kiss the sky"--Jimi Hendrix)
"Baking Carrot Biscuits" ("Taking Care of Business"--Bachman-Turner Overdrive)
"Last night I dreamt of some bagels" ("Last night I dreamt of San Pedro"--Madonna)
"I've got shoes; they're made of plywood" ("I've got chills; they're multiplying"--Grease)
A childhood belief about misheard lyrics

others believed things like this
- I used to believe that people could fly during thunder and lightning, because I dreamt this once— Minimania
- I used to think Jimi Hendrix was white, and Eric Clapton was black.— Steve
- I used to think people didnt actually kiss on tv,i thought that the computer just made it look that way.— deanna
- My favorite excuse:
Must be those trouser geese again!— Tootie Fruity - I used to believe that if i took the covers off at night i would freeze to death.— RockerGirl
- I used to believe that if you kiss a frog then the would would really turn into a king.— jing