I came to my own conclusion that pepper was various kinds of ground up stuff, including radishes to make it spicyhot. (Because, what other vegetable is spicy like that?)
A childhood belief about general

others believed things like this
- I used to believe that if you dig a hole in the ground and put pepper in the hole, the ground would sneeze.— Cookie
- I believed Dr. Pepper was pepper-flavored medicine and was afraid to drink it.Anon
- I used to believe that Dr. Pepper actually tastes like Black pepper. I'm still afraid to try it.Anon
- i used to think if i would eat spicy food i would burn and die— Bill
- I used to think "firecrackers" we're some kind of really spicy cracker.— MAG
- I used to believe all liquids were water-based with things added to it to make different kinds of liquids.Anon