Yes, Sylvia, people age. That's a keen observation. Apparently it happens to every human being on the planet. As we get older, cellular turnover slows down, bone resorption shifts the facial structure, and gravity takes over. Faces hollow out and things sag. How quickly that happens just depends on the genetic phenotypes someone carries.
Dean looks exactly like a fit, healthy guy at his age should. He looks incredible, and frankly, it is great to see him looking more like a man instead of a boy.
