Where Does School Spirit Come From?

I am having a problem trying to find out what is the cause of school spirit.  You know, the excitement you get when your home team is playing against a rival school; the anger you get toward some one that talks about your school; the urge to join the cheerleading squad, and even some of the many teams available at school.
I myself don't have the "joy" that many feel about their school.  Maybe it's because I hate it so much or maybe because my school is not really known for sports as much as academics and ugly uniforms.  I've been going to this school since I was in the 6th grade, and I can't really remember the last time I liked my school. . .wait, I think that I was in the a 6th grade, a dumb naive 6th grader that thought it was so cool to being going here, but little did I know I was going to have hell to pay for not getting accepted into that White private school in the suburbs; I endured verbal abuse by a lot of the boys and girls, and I did nothing wrong!  It took me four years to finally find some real friends!  But I'm in a happier place now.  Still, though I am in my senior year, I can't find the "heart" to have any school spirit!  I've always hated the pep rallies, and I can't express how happy I am to know that I might miss the one this year!
Anyhow, the thing that got me asking this question is my sister has decided to join the high stepping team of her public school.  Her school is a historic Cleveland public school that has produced so many distinguished alumni including the creators of Superman, and a host of numerous football stars.  If you ask me, I would rather be going to my school than theirs because the Cleveland school system is so horrid!  At least my schools has its academics together, but in the meantime, their school has a whole lot more school spirit than all the kids in my school put together.  Actually, I think that every school has a lot more school spirit than my school!  Shoot I have school spirit for Ohio State way more than I do here, and I don't even go there!--yet!  So my conclusion:  School spirit, for my school anyway, if anyone would have any, comes right out your asset!    Freak my school!  Go Bucks!