I really like football. I can't exactly point to one specific reason or event as to why. My parents watched pro-football but they weren't fanatics. I don't even know if they pull for any particular team now that i think about it. My brothers didn't play it in high school; i did go to some games then, like everybody does. I went to LSU, which is a football school, but i only went to 3 games when i was there. *hangs head in shame* We kinda sucked then, between 1994-1998, so i do have an excuse.
But i don't just watch one team. I'll watch any pro game that is on, pretty much any college game too. While i have a better knowledge of the goings-on in pro football (only 32 teams to keep a grasp on) or SEC football (we're down to 12 here) i have a decent grasp of the rest of the college league. I can't name every quarterback for every pro team but i could name 2/3 of them, i can parse out all the pro teams in their respective divisions and how they ended up for the year. i understand offense better than defense but i am learning that more too (3-3-5 is fun to watch!) Living in an AFC town i preferentially watch AFC teams and follow the Titans, Chargers and Steelers the most.
I found college basketball a few years ago. We started going to Vanderbilt games when BF still worked there. My heart was broken when the good priced season tickets sold out before we got any. And now they are 15-0! and have an attractive Australian freshman! While i will watch random college games i do that less than i do for football; pretty much SEC is all i watch. I still don't understand a lot of what is going on but i have progressed much since the first year i went. In a key game, at a critical point (were we down or ahead by a couple, near the end of the game), the other team let the shot clock run out. Everybody starts cheering and i am jumping up and down yelling "turnover on downs, turnover on downs!" I thought BF was going to pass out he was laughing so hard.
Baseball is, well, baseball. Much slower, much more sitting and waiting for something to happen. 3 game home stands can make or ruin a weekend. I can't say i keep up with any baseball except for Vandy. I can't say i have any desire to follow another team either. I enjoy going to the games, the communal experience. Everybody may cheer when Vandy scores a touchdown but at a Vandy baseball game everybody stands up and sings "Sweet Caroline" for no reason at all!
I don't watch soccer, or car racing, or pro basketball, or tennis, or pro baseball, or golf. so i am not a compete sports head.