In the song 'fear of the dark' (Iron Maiden) I used to think it was 'fear of the duck'. Couldn't quite figure why everyone was so afraid of that duck...
A childhood belief about misheard lyrics

others believed things like this
- i thought that "aromatic" duck was actually "asthmatic" duck.
poor thing...— rachael - I always thought that duck sauce (from chinese restaurants) was duck poop.
— emily - I thought the lyrics to "Don't fear the reaper" were "Don't fear the reefer"— who new?
- Whenever I was upstairs on a bus, I didn't believe that it would fit under the bridge so I used to duck. — Dave, Lancashire
- I used to belive that if I didn't duck when going under bridges they would hit me.Anon
- My mother's name was Anna. She was called "Annemor"(Duck mama). I was convinced I was a duckling.— Christine Norway