I misheard the "church on time" lyric in David Bowie's "Modern Love" as "ching chong chang" and wondered how such a racist song was allowed to be played on the radio!
I used to believe that both Madonna and Michael Jackson were dead when I was a kid in the early 90s. I thought that every concert and video I saw of them on TV were old and that you could only get that influential after death (for me they were in the same category as Elvis).
When I was little, when the band "Linkin Park" emerged, I thought that the radio said that they were playing a song from 'years and years ago'. Being a kid who only liked new songs, I would switch over whenever they'd play. When I heard 'It is love' on the radio regularly though, I was surprised because I thought it was an old song.
When I first heard American Pie, I misheard the chorus as "buy, buy me some 'Merican pie". I didn't know why Don McLean couldn't just buy the pie himself.
I used to believe that yodeling was illegal in certain countries.
I used to believe "I Want Candy" was actually "I'm A Kidney", especially since they played it in PE/health class at my school.
When I was in Grammer school we sang a Polish folk song about how the "Vistula" ( a river in Poland) was flowing. I misunderstood and thought it was "fistula" for years.. Then someone told me a fistula was a boil you get on your rear end. Talk about embarrassed...
I used to hate that song about the Weeping Willow "crying on his pillow" because I thought it was an actual guy as opposed to a tree, and thought it was too sad. Then, I learnt that Willow was a girl's name and thought that maybe the man was actually named William.
I used to think bands or singers could be sued for plagiarism if they coincidentally had a song that was too similar to one by another artist, but not as a cover!
At one point, I believed that Lauren Mayberry was future me, but I'd got a hold of a time machine, and came back to the time when I was the age I believed this.