I used to commute to work on a small motorcycle. Sometime around age 40, though, I realized I was getting much better at imagining what it would feel like to hit the pavement or a guardrail -- things you just don't think about when you're a teenager or in your twenties. There are a number of age-related realizations like this: I quit smoking when I realized how weak my lungs had become; I drink a lot less since I realized that I don't sleep as well after drinking (not to mention longer recovery times). I also returned to cycling after several years off and now feel much better than I have in years. There are still creeping aches and pains, failing eye-sight and hearing, but I'm much more at ease with myself and I've learned to live better with age, and cycling is a big part of that, of course. Let's call it maturity, though, not "feeling young" or "feeling old."