Playing a sport is one thing, but what is the point of watching a sport for years?

I have faced this question in various phases of my adolescent life for a long time, and I did not have a satisfying answer, even to myself. I have been watching various sports for over a decade now, every week as well as playing a few. Many of my acquaintances, have never been indulged in spectator sports although they were part of some sport or another. I have had many discussions revolving this, but never I could understand the real importance of such a time waste looking activity to others, never to me.