Tonight I somehow arrived at a site discussing Parkour.  I'd never heard of it before, at least not using this name, and was curious.  So I started to read, and click, and watch, and have my mind blown.  The best way to sum up what I found is to say simply this: what I cannot do.

When I was a boy, we lived beside a school, and we used to spend most of our time there playing ball, skateboarding, and biking.  One of the things I was never supposed to do was climb on the roof.  Of course, we needed to climb on the roof almost daily, because we'd lose a ball up there.  I was never the one to do it, but my friends and brothers would always scale a wall in the back, effortlessly pulling their way up a pipe hand-over-hand.  I can even remember one of my friends jumping off the roof once, in an effort to get to the ground before an adult came around the corner.  It was awe-inspiring to watch them use their bodies this way, and I have never really forgotten it.

This is not what Parkour is, but this is what it brought to mind: the sense of one's body, spatial awareness, forward momentum, a knowledge of the limit, a reach beyond obstacles.  David Belle, the founder of the movement, says that he began exploring Parkour because of his father:

I was interested in the story of my father. People always said, “Your father did this and that he saved people,” and I wanted to know why – what he was doing? He explained to me, ‘that is Parkour.’ I asked – ‘what is Parkour?’ and he told me that in Vietnam there are different kinds of Parkour. The more he told me the more I wanted to experience that myself because he did that too.
I think this video, among the dozen or more I watched, gives the best summary of what it's all about:

I don't have these skills, but I respect them, and remember a time in my life when they were available to us as adolescent boys in ways I can't imagine now.  Incredible.