all grown up

I know first graders are not all that old, so why do I feel like Samuel is all grown up? He can read now and do math and on Sunday he rode his bicycle to school all by himself (Ok I was following behind him in my van like a lunatic. But still...). It is not just that he is doing these things. I guess his grownuppedness (is that a word?) stems from the fact that he is gone all day Monday through Friday and is creating a life independent of his life here at home. He has friends I've never met and experiences I know nothing about. And, quite frankly, I am not ready for it! I know this is the plan but part of me wants to keep him little and innocent forever.