I have to say the benefits really did make me a better deal as an employee. I basically went from someone who did things because he had to, just fitting everything in around work, to someone who pursued his own goals. Now that I'm back at work, I don't constantly lose sleep till I have to rush to work at the last minute; I schedule things so I don't have to, and I got my sleep habits under control. I don't bike to work just because I need some way to keep from getting fat; I sought out active, fun hobbies I can still engage in, like ice skating. I don't beat myself up all the time for being lazy; I have my own strategies now for getting myself to put in time on the right projects and not let things slip away. I also used to have trouble just getting basic things done like phone calls and finding a tailor; with my time off, I got things done and gained confidence that I could get any errand done.
I also feel so much more independent now. Google Maps plus free time to explore means I found so many wilderness sites and activities. Internet reading about joints plus time to work on the exercises mean any ache or pain that comes up is something I can solve. Compared to the time I tore a back muscle falling into a railcar, when all I could do is try to reduce the activities that caused me nerve damage and hope I got better, I'm so much better equipped to take care of my own health.
tl;dr Having full responsibility for yourself is great. I did a lot of things it would have been too late for in retirement, and the best part is the habits I learned when I had time are now ingrained enough I can do them even while working full time.