I used to believe (until I was 14, actually) that a gherkin was a type of shaggy goat.
A childhood belief about gherkins

others believed things like this
- Up until 5 seconds ago, I had no idea wat a gherkin was— It's a little cucumber, stupid!
- I used to think that a gherkin was some kind of piece of machinery. I wonder where I got THAT from...— Some Idiot
- When we were little my sister thought if you mixed cow’s milk and water you’d get goat’s milkAnon
- I used to believe that a pigeon was a type of pigAnon
- I used to think giraffes were a type of horse— Crocotta1
- i used to think that if you picked your nose you could eat it because it was a type of chicken.— nutter