This question rumbled around in the back of my head for some time. The first time it really struck me was in the early winter of 2003. I was out walking my dog the morning after a sharp drop in temperature. The night before it had rained, and there were some frozen puddles on the sidewalk. I was looking at these frozen puddles, when the child inside me had the impulse to step on them and hear that wonderful crackling sound. It was then that I stopped to consider, what was it that makes that fun? I realized it was the little boy version of myself who wanted to do that (which I did eventually indulge). Furthermore, it was the thrill of breaking something, an activity that little children relish, which was being sublimated. Somewhere inside many of us, including kids, is that primitive childish impulse, but why?