I look at myself, and I'm all hard, grizzled and scarred. Then I look at Brad Pitt who's actually a few months older than I am, and I'm struck that I look 15 years older than he does.
Maybe. However, A.) chances are Pitt shows his age much more in person than in photos. B.) Pitt has had a fairly pampered life since he was about 20 or so avoiding manual labor and indulging in the best anti-aging skin creams, health spas, physical trainers, etc. that money can buy. C.) Stress ads to aging and when one is as extravagantly wealthy as Pitt is, many of life's stresses are minimized. D.) Pitt hasn't really had the reputation as a hard partier. Look at some of the rock stars roughly his age --any of the guys from Motley Crue for example. They ain't looking so good!
So don't feel too bad! There are many logical reasons why Brad Pitt is still good looking whereas you are grizzled and scarred. And poor Jennifer. She's not aging nearly as gracefully as he is!