I look far better at 60 than I did at 50.
I am not a fanatic, especially about the dietary part, and I have the limitations of my gene pool and my age, so I am not cover-boy material. In fact, part of why I go so regularly is so that I can eat what I like and still stay in decent shape. The last year I slacked off a bit and gained some non-muscle weight, but that is coming off slowly but surely.
There is a definite narcissistic thrill to being in good shape, especially if you are not born with a naturally athletic frame and have spent parts of your life not so comfortable in your body. Funny moments happen, like this week. I was helping a friend do some moving. It was a hot day, so I was just in jeans and a tank top. I turned a corner and looked up into a large plate-glass window with some reflective quality to it. I saw this...well, I'm gonna say it...big, strong, nicely built and handsome dude looking at me. And a nanosecond later I realized it was me. Very funny. I turned to my friend and said, "Is that really me?". Eyes rolled.
But the regularity of gym exercise has a variety of benefits, not just the change in physique. Someone else has laid them out, very well. I concur completely.