Why do I ask myself why?
A little perspective...
I'm 46. I have always been active and the type of guy to work until there's no more sunlight, and that's just how it is. I took for granted my ability to complete tasks all day long until I broke my foot. I had never been incapacitated until that happened, so I was in for a rude awakening.
Anyway, I've been slowly healing and my ability to get things done has increased, and as that happens, I am SO happy when I see what I've done.
I guess my point is we should never discount our accomplishments. Whether we're 75 or 25, there are always mountains to conquer.