A wiggly tooth

We discovered today that Danny has a loose tooth. He smiled this morning and I noticed one of his bottom teeth was pushed forward. The average age to lose a tooth is 6 so we are young. He did get his baby teeth very early though. I talked to him about how there is a grown up tooth underneath that is growing and making the baby tooth wiggly. Eventually the baby tooth would fall out and the big tooth would grow. His response was, "I just want to keep the old one. " I then explained the tooth fairy, still not happy. Oh and did I mention the tooth fairy sometimes brings trains? He's now trying to extract the tooth himself.