When I was little my dad told me that the reason the tooth fairy (!) left money under the pillow was because they used to make our teeth into flower pots!
A childhood belief about fairies

others believed things like this
- when I was little I believed that if I put a white stone under the pillow with my tooth I make more moneyAnon
- I used to think that the tooth fairy puts you in a deep sleep before stealing your tooth/teeth.Anon
- I used to believe that in the tooth fairy took all your teeth and built a tooth city for her to live in!Anon
- My mother told me that the tooth fairy would only come if I brushed my teeth.— Dale
- when i was a child i used to believe if i put my tooth under the bed the tooth fairy would give me money— milena
- My nephew refuses to put his tooth under his pillow in case the fairy burns him with her wand.— Nina