My brother used to think that olives came from two different kinds of tree: one that make "normal" olives and one that make olives already rattled off
A childhood belief about general

others believed things like this
- I thought the Mountain of Olives was made out of Olives— Tanuki
- I used to believe that black olives were made out of whale skin.— Troyson
- my dad once told my bother and i, that olives with pimento, were fish eyes. — jocelynn
- A friend of mine thought that some olives grew with red edible pits (pimentos).— HA
- I used to believe all liquids were water-based with things added to it to make different kinds of liquids.Anon
- I thought Pink's "You make me sick" was "you make me sick, you make me look like a candlestick" LOL— Rice