I doubt there is any treatment for that.
should you ever resign

So what you're saying is you suicide your won games?
I've met some odd/eccentric chess players, but you're really trying to top the list, aren't you?

That is like forfeiting for someone else. Shouldn't it be his job to forfeit once he knows he's beat?

It's got nothing to do with prolonging and rubbing it in. A game of chess can always take unexpected turns or twists. You never know what's going to happen, especially when you're playing someone you don't know.
Always play till the absolute end.

That is like forfeiting for someone else. Shouldn't it be his job to forfeit once he knows he's beat?
Not only that, but you also robbed him of a learning opportunity. It requires a lot of thinking to turn a lost position into a win, which would have given him experience for his next game.

cont. from last post. I'm currently playing chess with a friend of mine who is a bright person, but kind of a beginer at chess. we talk a bit during our games, not too much, but i try & pass along some of the tips afforded me in early chess playing. well, we recently played a game in which he played well. he made a mistake & i was able to capitalize on it. he few moves later, he kinda knew he was beat. that'S when i toppled my king. point being, i'm much more comfortable forfeiting when i know iv'e won rather than when i'm still fighting
what the...?

I agree, resigning in a won position is insulting and a little conceited. You should never feel you HAVE to resign, let the other player work for the win, there is no obligation to resign just because you have a lost position, that forces everyone to play solid chess - after all, they say the hardest thing is to win a 'won' position.
Conversely, people should feel no shame in resigning if they feel they've lost and have nothing else to learn, for example, if they hang their queen they might prefer to start another game with better chances. For the 'winner' they should be comfortable both with an early resignation (a win is a win) and also, not get irritated if someone refuses to resign, they may wish to play on and learn what they can and even look for a chance to turn it around, there is nothing wrong with that.
cont. from last post. I'm currently playing chess with a friend of mine who is a bright person, but kind of a beginer at chess. we talk a bit during our games, not too much, but i try & pass along some of the tips afforded me in early chess playing. well, we recently played a game in which he played well. he made a mistake & i was able to capitalize on it. he few moves later, he kinda knew he was beat. that'S when i toppled my king. point being, i'm much more comfortable forfeiting when i know iv'e won rather than when i'm still fighting