when i was a child i always thought the the first line of the song 'run to me' by The Bee Gees was ''if ever you have got brain in your heart''! i used to think it's a song by count dracula (god knows why) who asks everybody to run to him whenever somebody has 'brain in their heart'!
A childhood belief about misheard lyrics

others believed things like this
- The song called heart of glass mixed me up as a kid. I heard "Heart and ass". — oops
- I thought the song "Party Time" by Moby was actually saying "heart attack" (this was before I knew the title)— Elviessa
- I thought that Count Dracula was the count from Sesame StreetAnon
- 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 my brain would explode if it was in the sun too long— Heather