Disappointment and euphoria are still very close. The excitement of a win is almost physical. Especially when the battle was tough.
Lately I enjoy a win most when I haven't made any mistakes after setting up a positional game and close it in the end game. No mistakes? Well, no obvious mistakes. As Lasker one said, 'if you see a good move, look for a better one'. I guess that you have to have an iron discipline to do that move after move.
The difference with a defeat today, compared to my teenage years, is that I am able to overcome it quickly, after analizing the game, and admiring the tactics of my adversary or the stupdity or even ignorance (was hit lately by en passant pawn moves, which I considered 20th century :-)) of my own play. At the end I do enjoy the golden opportunities of learning.
I love the game, any way you look at it. A cool combination or fine tactic, by me or the other, I can savour.
And sometimes, when I am tired and a bit aggrevated by the going-on-and-on of a positional play, I play as an addict. You know ... play the moves just for the sake of playing. Most of the time this will get me 'killed' ... :-)