"Achy Breaky Heart" by Billy Ray Cyrus was popular when I was a kid. However, I misunderstood the line "He might blow up and kill this man." I thought "this man" was referring to some other specific man - in short, that his heart would explode so violently as to cause collateral damage.
A childhood belief about songs

others believed things like this
- The song called heart of glass mixed me up as a kid. I heard "Heart and ass". — oops
- I used to think that when people had heart attacks someone came and stabbed their heartAnon
- I used to think that if you eat pig heart, you could grow another heart and be twice as healthier. Anon
- I thought you always die if you A. get cancer or B. have a heart attack— Nate
- I thought the song "Party Time" by Moby was actually saying "heart attack" (this was before I knew the title)— Elviessa
- I used to believe an artichoke was an animal and we only ate its heart. — Laura