Aristotle first identified the problem. Suppose your life is made up of things you do for the sake of something else — you do A in order to get B, and you do B only to get C, and so on. Therefore A has no value in itself; its value lies in the B. But B has no value in itself: that value lies in the C. Perhaps we eventually encounter something — call it Z — that’s valuable for what it is in itself, and not for anything else. The grim alternative is that we encounter no such thing and satisfaction is always deferred, always just around the corner (indeed many would argue that this is the treadmill of consumerism). If our lives are to mean anything, there must be something that’s valuable for what it is in itself and not for anything else it might get you. This, in the parlance of philosophers, is called intrinsic value. Most obviously, we should be able to find intrinsic value in the other people in our lives. If we focus just on our activities — on what we do — then it is clear that it will not be found in work (in my sense above, of things we do for something else) but only in play. It is play, and not work, that gives value to our lives.
Alan Watts talked about this sort of thing a lot:
When we make music we don't do it in order to reach a certain point, such as the end of the composition. If that were the purpose of music then obviously the fastest players would be the best. Also, when we are dancing we are not aiming to arrive at a particular place on the floor as in a journey. When we dance, the journey itself is the point, as when we play music, the playing itself is the point.
I wasn't exaggerating when I said that woods-moseying was my "purpose" in life. Of course, I could just as easily have named reading, blogging, watching soccer games or listening to music, too. Am I suggesting that everyone should be similarly lacking in worldly ambition? No, I'm saying that there is no "should" to begin with, no categorical imperative, no final destination toward which all our efforts are aimed. I'm saying that my conception of the good life involves activities which exist simply for their own sake, as reflecting pools, pools in which such progressivist, teleological delusions of ultimate purpose can drown.