How can some one win when it means that some one else loses?

I think that a lot of people would clean their arse with this question (see title) but, if after letting the question sink in you want to share your thoughts on it, I would appreciate your response. Thanks in advance.

This is my take on things:

http://en.lichess.org/forum/general-chess-discussion/just-had-a-horrendous-losing-streak-but-#1

If both players get to have a nice game of chess, has anyone really lost?

"All games are aberrative, some games are fun." L. Ron Hubbard