Child: One of my teeth just fell out!
Adult: Well make sure you put it under your pillow tonight before you go to bed.
Child: Why would I do that?
Adult: Because the tooth fairy will bring you money.
Child: Wait what?
Adult: The tooth fairy will give you money for your teeth.
Child: You mean to tell me that someone is going to give me money for my teeth?
Adult: Yes of course. Actually there's a large market for human body parts. Kidney's, bone marrow, liver, even breast milk. In fact, you have to be careful, especially when you travel because people have been known to wake up in a bathtub full of ice with one of their kidney's missing, which they later learn has been sold on the black market.
Yep, there's a big, big market for human body parts.
Child: ... ... ...