motivation

Last week someone posted a message on the forum at triathlete.com asking folks to describe their motivation, Its a pretty tricky question. I can tell you that four years ago when I was training for my first Olympic distance race (1 mi swim, 25 mi bike, 6 mi run) my motivation was to train a lot and prove to myself that I could complete and compete in a race that challenging. Pretty simple motivation, but it got me out of bed to go to the gym (or on the bike, or to the track) and kept me from drinking all summer long.
But now I'm not sure what my motivation is. A comeback? I guess, but I don't anticipate I'll be competing t the same level since I don't anticipate training as much. Its kind of funny for me to talk about competing at the same level, since I've always been a mid-packer, but I am one of those people who likes to measure progress. I may finish 50th in a race, but as long as my times have improved (and I haven't come in dead last, of course) then I am pretty happy with the result. So what is my motivation when my expectation is that my times won't improve at all? I guess to see how close I can get with the amount of training that I can do. And to get in better shape, of course. I wish getting in better shape was my only motivation, but I am a competitor by nature, even if I'm only competing with my past.