theory of relativity
When I spend a good deal of time w/ MsM, I look at J-man and think what a little guy he is. And then we spend some time w/ my brother and his family and I compare J-man w/ his cousin, Jack ... I think what a big boy he has become.
My theory of relativity is quite simple. If you want a sense of how old your children are becoming, have them interact with those younger than them. You'll be shocked how time has flown. And when you want to see how young and innocent they still are, surround them with older children. You'll be pleasantly surprised how much of their lives they have ahead of themselves.
Works every time. :)