How well do you age?

I was just wondering why people age differently, and I have come to the conclusion that it all depends on how well you take care of yourself as you grow older. I am now 39 years old, I have always stayed away from drugs and alcohol, and I am often mistaken to be in my mid twenties. I think that it is a good thing and I always thank people for the compliment. When I reveal my real age to someone, they are often shocked. There are a few women that I used to hang out with in high school and they all look a lot older than they really are. I still look the same as I did in high school because I've always taken good care of myself. Do you know anyone that has aged beyond their years? Why do you think that it happens that way for them? What about youraelf? Do you look younger than you actually are, or do you look a lot older?