From "me" to "I"

Sean has always been very verbal child and so he is always learning new words and improving his vocabulary each day. Until recently, he started all sentences with "me" instead of "I". Recently, he has made the switch to "I am awake" or "I want a fork". He just is growing up so fast and because he can communicate so well he often seems older
than he is! The other day he was frustrated at Dan and said this exactly word for word "stop doing that right now, Daddy" Geez! Are you 2, or 15? Plus, he often calls me "mom" instead of "mommy". I'll take either but I prefer to keep him in the little kid phase as long as possible!