Can someone explain to me why people who are not athletes get so excited about sports?

I just don’t get it. I have several friends whose favorite thing to do is talk about sports, go to games etc, but they are not nor have they ever been athletes. My one friend has been to every MLB stadium in the nation, but he’s never actually played baseball. I don’t see why you would get that much enjoyment out of it if you neither (a) played the sport yourself and enjoyed it, or (b) have some kind of relationship with the participants. In most cases neither of these are true, so can anyone explain this to me?