I don't remember this, but my parents told me. When I was 2 we had a dog and apparently I thought "tail" meant "butt". I fell down and informed them: "My tail is hurting."
A childhood belief about general

others believed things like this
- I used to believe that a cat's butt hole was on the tip of his tail.— PANTS
- We told our little sister that she had a long bushy tail and she fully believed us for ages!!Anon
- When I was very little, I used to believe that bacon came from the tail of a pig because it was curly!!— Audrey
- I used to believe that if I wagged my dog's tail, it would cheer my dog up.— GED
- I used to believe that if you hit your tailbone, a tail could grow out of it.— Ida
- My Dad convinced me that Manx cats had no tail - and only three legs.— Jim