My mom almost wrecked the car when she heard my sister and me singing along with Helen Reddy: "Yes, I was, but I squeezed up all the paint!"
Turns out she was saying, "Yes, I'm wise, but it's wisdom born of pain." That doesn't sound like near as much fun.
A childhood belief about misheard lyrics

others believed things like this
- When I first heard Matt Monro's song "Born Free," I thought he was singing "Porn Free."Anon
- My sister once asked her mother why she didn't paint her black....Anon
- I used to think that the sound after the toilet was flushed was ladies singingAnon
- I believed that I had a fake right big toe, having lost my real one in the plug holder (thanks Helen!)— Mike
- I always believed as a child your stomach was a big hand which squeezed your food out through your bum....— amc
- I used to believe that Jesus and all of the wise men lived under my bed. — wuteve