cage fighting

I have never really understood why people would want to beat up someone else in a controlled environment. My room mates would watch UFC sometimes and as I would walk by the TV to my bedroom, I would just shake my head and say, “what is the point of this “sport”? My confusion for this has become greater ever since I had to cover a cage fighting exhibition last Saturday. These young men, weighing between 130-250 lbs would become tangled up with one another, dancing around the cage, swinging and kicking till one went down, and when he did, his opponent would jump on top of him and beat his face till blood was drawn. If he wouldn’t give up after getting his face beat in, his opponent would put him in a choke submission till he passed out. The ref would stop the match, the victorious fighter would parade around the cage, the medic would run up to wake the passed out fighter and when the loser became conscious, the winner would take time to thank his opponent and give him a hug and say “good job”?? What the heck? One minute you hate his guts and want to kill the guy and the next minute you guys become friends? I may not ever understand this “sport”.