At the last place I worked at 3 of the lads thought on the song Down under by Men at work were the lyrics:
I said do you speaka my language
He just smiled and gave me a bite of his sandwich
Also when I was about 11 I thought the crowd in the Fulwell were singing:
Stiggy is a wanker
I asked my brother who Stiggy was and why he was a wanker and when he stopped laughing explained it was:
Singing in the Roker
What are your favourite misheard lyrics