I used to think that a "Long Island Iced Tea" was simply iced tea that got spiked with rum.
And when someone mentioned "dry county", my first thought was that it did not rain there much. But this it did not take me long to figure out that it meant that they did not sell alcoholic beverages there.
A childhood belief about drinks

others believed things like this
- I used to believe that if you poked a cloud with a really long stick rain would come out.Anon
- I used to believe that, no man drank hot beverages, because my father never did. — Sue
- My dad thought when he was little, rain was caused by army guys in the clouds with rain guns. — Daughter of the Weird
- I used to think a female daddy-long-legs was called a "mummy-long-legs".Anon
- Up until I was about seven, I thought soda pop was alcoholic and that's why kids weren't allowed it.Anon
- I used to think that County Durham was in Ireland.Anon