All of my kids have played sports of one kind or another as they went or continue to go to school. Sports, like wars, generally have winners and losers ... that's the way they are configured.
And one of the hardest things to do is to convince a kid to be gracious in victory. Even though they too have been on the losing end of the battle and know what that feels like, still they can't help gloating and strutting...sometimes in public and less often in private.
As I understand it, Alexander the Great may not have been entirely benevolent when he conquered vast lands and made them part of his empire, but one thing he did do was to make sure that natives of the land were a large part of the new administration... loyal to Alexander's vision and desires, perhaps, but still, speaking the native tongue and aware of native needs. He may not have been gracious, but he certainly was savvy.
A victory is one thing, but a victory full of gloating becomes no one, least of all the victor.
Not to mention the fact that gloating is bound to come around and bite you on the ass in a future tainted by chest-pounding.