How "grown up" are you?

I am 45 next year, but the body feels absolutely hammered. Partner but unmarried. What constitutes being grown up aside from the usual responsibilities of life. Probably because there is no such thing as being grown up other than being to procreate. The advent of time obviously changes things across the board, but probably why myself and my forties something friends, could not give a hoot about being a "grown up" Means absolutely nothing :D

Fulltime job as programmer, living with my girlfriend for about 6 years who is a teacher. Grown up? Not at all. A few days ago we got a little football as a promotional gift and spent an hour running through the apartment shooting it against the furniture.