When I saw a conductor leading an orchestra, I thought that every time they moved their hand, it represented a different note. I wanted to join the school orchestra, but I was worried that I wouldn't be able to remember which hand gesture stood for which note. Now I play the violin, and I am satisfied to know that I don't have to memorize hand gestures. :)
A childhood belief about songs

others believed things like this
- I used to think that my right hand wasn't my right hand anymore if I turned around.— Mike
- I used to wonder how they managed to fit the orchestra into the radio station.
— sally - My teacher held out a hand to say, "stop" but I thought she wanted a high-five.Anon
- I thought second-hand smoke was bought off eBayAnon
- I thought that the word Copyright was like copying your right hand on the copier.Anon
- I thought the big hand was for the hour and the smaller one was for the minutes until i was in third grade.— Time Challenged