I am 54 and I remember that day I walked over the line. I thought it was no big deal then I started to get depressed. That lasted a few days and then I got on with life. I now look at every day as another gift and try to enjoy it. Things changed, in my work I am now considered less an agent for change and more as a resource full of experience and sage advice and a mentor for the next generation - better that than a curmudgeon. They know my time there is limited, only 5 or 6 more years. I feel healthy and vibrant, my bum knee bothers me a little more than usual and I struggle more with keeping my weight in check.

You are probably in better shape than most of your peers. That just means that the odds are good you will have a better quality of life for a longer time. Enjoy it!