When I was 19 I found out that pickles don't, in fact, grow on trees as I had always thought. I picked up a short little cucumber and said "Gee, this is just about the size of a pickle" and had to sit through my boyfriend's entire family laughing at me.
A childhood belief about gherkins

others believed things like this
- I used to believe a pickle was a smaller version of the cucumber.Anon
- I used to believe that pickles grew on trees and didn't come from cucumbers.Anon
- Hasn't everyone, at some point or another, believed that pickles grew on trees? I sure did.— Matt c.
- Up until the age of 21 I believed pickles were pickles, I had no idea they were cucumbers.— Jason
- I used to believe the pickles were the fingers of martians. Because of that, I did not eat pickles.— alexandre, a French student in eighth grade
- I thought that broccoli were just trees that didnt grow all the wayAnon