There was a song I misheard when I was really little. I don't know the title, but I thought it went like this:
I tut (like king tut) you once, I tut you twice
A walnut cold at any advice
(That's all I remember. I wrote down my wrong lyrics somewhere, and it was at least the whole chorus.) I always assumed it would make more sense when I got older. And it did, but only when I found out it went like this:
I touch you once, I touch you twice
I won't let go at any price
(at least, I think--my hearing's better now, but I've never really looked it up.) I don't think that would have made sense to the little kid me either ;)

NotRlyAretia

I thought the line "Gina works the diner all day," in Bon Jovi's Livin' On A Prayer was "Gina wants to die of old age,". My friend thought it was that too ...

Peppermint Penguin

Swedish country and pop singer Kikki Danielsson scored a 1986-1987 hit with the song "Papaya Coconut" (which she also recorded once again with Dr. Alban in 1998). I used to belive she sang "Pattaya Coconut", refering to Pattaya in Thailand, famous for it's child sex tourism (Actually it's true that the song lyrics refer to holiday travels to warm places).

Johan

For the longest time, I thought the song "Paperback Writer," by the Beatles was actually called "Paperback Right Turn."

Anon

Kentucky HeadHunters Song "Dumas Walker" I thought the lead lyric was "Were all going down to do Ms Walker..."

Jeremy Alsup

Tom Cochrane's song Big League says "Sometimes at night, I can hear the ice crack."
For a long time, I believed it was "Sometimes at night, I can hear my ass crack."
The next line (and this is true) adds to this by saying "It sounds like thunder and rips through my back."

Oh Tom... There's medicine that can help with that.

CAM

I first thought Taylor Swift's "Teardrops on My Guitar" said Teardrops on Rocky Top. And I would sing it wrong, very loudly, in my car.

Anon

I thought the words to Heart Shaped Box by Nirvana were "hey, wait, I got a real gold plate," instead of "hey, wait, I got a new complaint."

bagface

I thought David Archuleta's song Crush said "where this sneaker go" instead of "where this thing can go".

Kim

I used to think Michael Jackson's song 'Liberian Girl' was 'Librarian Girl'. I quite liked Michael Jackson's admiring of the quieter woman.
The lyrics later on in the song seemed to fit in with my belief as when it says 'Naku Penda Piya - Naku Taka Piya- MPENSIWE', I thought it was 'Naku Penda Piya - Naku Taka Piya - MY PEN'S AWARE . (Librarians use pens alot)

Anon

When I was young, my hearing was much worse. I always heard the Paul Simon song "Call Me Al" on the radio and until I was 10 and found out the real name of the song, I always thought it was called "Cornmeal", and wondered why a song about corn was so popular.

Alf Was Here

My best friend used to sing the line in Garth Brooks' "Much too young to feel this damn old" where he says "lonely women and bad booze" as "lonely women and baboons". She did that until we were 17 and I heard her and started cracking up!

Molly

The song "Chasing Pavements" by Adele goes like this:

"Should I give up, or should I just keep chasing pavements?"

For the longest time, I thought it went like this:

"Should I give up, or should I just keep chasing penguins?"

gnat

When I was younger and my friends came over I wantd to act cool and know all the words to a song they liked soo when they played it and they were singing I would say the last word of every line and it would look like i was singing it

What is funny about this is that now when my other friend come over not the same one thought she does the same thing but she thinks i don't notice it but i do!! :p

Emily

I used to think the lyrics in Madonna's 'Material Girl' was 'Cos everybody's livin in a material world, and i am mom material girl' I just thought it meant she was the leader or 'mother' in this material world of hers :D

Jay