Not me, no sireee. I (ahem), passed a certain chronological milestone a few days ago and realized I should probably put my thoughts down about it. Trouble is, I'm not really thinking about it that much. It will sink in later when I have to fill out a form where the age range is something like 20-29, 30-39, Ancient and decrepit, etc. Age is clearly a state of mind, but it's something that the younger take great pains in reminding you of. Apparently they're going to be young forever.
I'm fairly happy where I'm at in this part of my life. I have some regrets and some accomplishments I have yet to achieve, but my age isn't going to preclude me from reaching them. It's safe to say that I still wouldn't make it in professional sports even if I could be eighteen again. I hope I'm only at the midpoint of my life now, I'd like another 40+ if I can have them.