On Saturday, I did my exercising down in the park in faultless spring weather. It might have been a touch on the cool side, but I loved the feeling of amiability in the air, as if all the rough-and-ready assertiveness of winter is over for good. Everything seemed gentle and obliging. The air was still, and the grand trees in the park were so motionless they seemed to be waiting for something. I hiked up and down a hill near an enormous oak, whose great branches leaned over the greening grass in an utterly peaceable way. Each time I got to the top of the hill, I would pause for a moment to take in the view of the glassy pond and the swirling ripples the passing breezes caused on its surface. My workout session was more like fun than work. It was exercise of a most agreeable kind.