For me, keeping a record was de-motivating, after a few years. If I didn't meet my "goal," whatever it was, distance, speed, etc., it bothered me. I took myself off of Bike Journal last year and I have been much more motivated.
Part of it, is that I have become a bit slower. Or, my average can vary widely. Whatever it was, it was starting to make me dread riding. Of course, I still have my computer to keep track of my miles, but at least half of the time, I don't look at my average. That way, I don't feel pressure. I know I can out ride most people my age (in the general population), but I am never going to be in the fast group. Since I am 56, this is fine. I have no affinity for technology and using stuff like GPS doesn't give me a "thrill" so my strategy is working.
I had to put this all in perspective; I have burned out on other sports and I didn't want this to happen with cycling.