I have to go see the dentist tomorrow for a checkup.
I don't like going to the dentist because I'm scared that he'll find some problem.
You know, how come if you crack a tooth or get a cavity it can never heal naturally? You have to get it fixed by artificial means by sticking metal or ceramic or something to it. I mean, if you break your arm, it will eventually heal, but why can't a tooth heal? We think that humans are at the top of the evolutionary ladder but some animals are able to regenerate all sorts of body parts and recover from major injuries that will permanently cripple a human. You cut a starfish in half and each half will grow into a new starfish. Crabs can regrow missing limbs. Sharks can regrow new teeth. How come humans can't do that?