I used to think prune juice was called "pooin' juice", because you drank it when you were constipated. I thought the name sounded totally nasty!
A childhood belief about drinks

others believed things like this
- I thought that grape juice was called "great juice". Anon
- when I was little, I called coke and pepsi "Black Juice"— can I have a refil on the black juice?
- I thought "Angel of the Moring", by Juice Newton said "just brush me teeth before you leave me"!!!Anon
- as a young child i thought poo was brown from eating chocolate and pee was yellow from drinking apple juice!Anon
- When I was little, I used to believe that snot was brain juice.Anon
- my grandfather told me that soy sauce was bug juice.Anon