Football. And I think it's an important thing we can learn from. I loved playing football. In Detroit, we played pick-up games of tackle football with no pads allowed but knee and elbow pads, no helmets. There were always games on weekends at a dozen or so high school fields. The people I hung with thought organized football with refs and pads and helmets were for pussies.
I could always watch any football game, and be interested in it. I winced at big hits and felt exhilarated on big plays. The teams I liked (Lions, Wolverines, Raiders), I felt like I was in the game. I played fantasy football, and really liked it.
After a year on hormones, I couldn't care less about fantasy football. After two years, I found televised games boring. After three years, I didn't even watch the Super Bowl. Now, I barely follow the Lions, and don't care about anything else. And I am sure the Lions-thing is only because they are the only hometown team that has not won a championship in my lifetime, and only won one playoff game. I'd say I don't care about them as a football team, they are just the ultimate hopeless-underdog.
My theory is that testosterone stimulates the parasympathetic nervous system, and estrogen represses it. In layman's terms, a man can feel what he observes on the football field, as if he was in the game. But women do not experience that, and I believe that is the direct result of the effect of hormones on the brain.