Most of us are born with an in-built sadistic instinct—we derive some kind of weird pleasure by causing or seeing other people suffer. It's not necessarily sexual in nature though; I'm talking about any kind of suffering, even the mental kind. The only question is to what extent we can control such inclination.
In the movies, when the bad guy, having caught the hero, and having his gun ready to fire, would not pull the trigger immediately. No—he would talk for a bit first. He would probably even explain why he has done so and so. Perhaps even throw in those sickening laughs too. To kill off the hero immediately without all the fun of seeing him suffer first would be dull, you know. It's just like when the cat catches a mouse; it would play with it first. It would savour its prey for a bit before finally eating it!
But it goes beyond movies; it happens in reality too. My uncle Tony is a little over 60 years old, and I can see very clearly such in-built sadistic instinct in him too. Uncle Tony has been playing the Chinese chess for many years, and he is damn good in the game! When in due course I got to play a few games with him, he would very quickly win a couple of my pieces. And from then on it's a matter of a few more moves before he would checkmate my king. But no, that would be just too dull; no fun in it at all. He would move his pieces one by one, gradually surrounding and bearing down on my king. He would ensure that my pieces would fall slowly one at a time until my king is completely naked! And then—and only then—would he make the grand entrance for the kill. Except that quite a few times, I found a loophole and checkmated his king when he least expected it!
In fact the sadistic instinct is a weakness in many people. Whenever I play chess or any games, I would try to finish off my opponent as efficiently as I can, that is to say, as quickly or in as few moves as I can. I'm not too overly concerned with those fancy little combination of sacrificing my queen, both the rooks and then mate with a mere pawn! The best policy in a competitive game is "no mercy for the opponent!"
Many of us, when obviously having the advantage over the opponent, can't resist the temptation of wanting to torture the losing opponent. We still want to win, of course, but we want to win in a dramatic and fancy way. We may even want to humiliate the opponent, thus satisfying our sadistic instinct. And then if we can pull it off in the end, it makes for something to be remembered—perhaps something to tell our grandchildren some day. We consider the fancy victory as a "sweeter" victory.
However, it is too easy to forget that even when one has an advantage over one's opponent, no matter how big that advantage is, that is still not a victory. The fight is not over until it is over! Some of us learn this the hard and embarrassing way.