The past few yoga classes, I have noticed that I have a Mona-Lisa style smile that I am able to maintain through most of the practice , though it does seem to shift to more of a grimace in those core twist that seem to test my edge. But I do seem to be riding on a wave of happiness when I'm on the mat. The other constant seems to be a plunge into the depths of my physical limits because I always feel like crashing after a class. This past weekend, after my Sunday and Saturday morning classes, it took me two or three hours to recover. I just felt completely bushed and sapped of energy. I have been working to improve my physical conditioning -- I walk up eight flights of stairs to my office two-four times a day, instead of using an elevator. I am just holding back the tide of aging -- after all, I am 56 years old. I can no longer just flip a switch and get in shape.

What intirgues me is that the conditions of smiliness (I can't bring myself to say happiness) and physical fatigue can coexist in the same body.