[beeworker]

I also have the same reaction, but not so much for the irrationality of being excited. Generally it feels good to win, and it feels good to watch someone you like win, regardless of why you like them. What I really really dislike about the affair is group signaling. (Which is a signal of my belonging to the small group of people who detest group-signaling, but nevertheless...) Enjoy watching the game all you want, even as a crowd, but the moment the "we" comes out I have that reaction. I see so many society-wide problems stemming from mere classification of people into groups, and the so-natural next step of individuals of those groups making the group part of their identity. One of the creepiest social experiments I know about is the Robber's Cave experiment: http://lesswrong.com/lw/lt/the_robbers_cave_experiment/