When I watched Zoboomafoo as a young child, I thought that in the "Animal Friends" song at the end of each episode, the line "Go make an animal friend today" was "A naked animal friend today", and I thought that what I misheard it as made sense because animals don't wear clothes.
A childhood belief about misheard lyrics

others believed things like this
- As a young child I thought that sheep and poodles were the same animal.— Jane
- When I was a child, I used to think that if you eat an animal, you become that animal
— Hmza - I thought for a long time that beaver and badger are the same animal— Ted Snow
- I used to believe an artichoke was an animal and we only ate its heart. — Laura
- I used to believe that an oilskin actually came from an animal called an Oil.....— Sally
- I used to believe that if you swallowed your gum that you would crumble up and smell like a dead animal !!!!— jordan