Even if you didn't go to BYU but you're Mormon it makes sense to be a BYU fan. I didn't go to BYU but I lived near by and my dad and grandpa were multi-sport season ticket holders. I've got a connection to it.
For some reason I've always liked the NY Giants. It's not a great team; I've never even been to NY and there are few players I care about that have been on that roster but for some reason I'm kind of a fan.