Staying focused and paying attention during your chess game is critical if you intend to win. While this may sound elementary, many players often do lose focus during a game and lose. When I was a very young man I went to a chess club meeting for the first time. I lost many games rapidly and was not at all considered a serious player. In the final match that I had that night, I played a much more experienced player who was said to be one of the very best in the club.
While I played him in our game I was very focused on the game and looking for any advantages on the board I could find since I knew I was outgunned. As the game progressed other members of the club came over and began to talk with my opponent. See, he was playing a young kid who had not even come close to winning a game all night. The distraction that my opponent faced with the conversation from other players allowed me to ultimately win the game. He simply was not paying attention, had be been focusing on the game he would of most likely won. I was quite pleased that he was distracted and unfocused during the game.
So the moral of the story is to stay focused on your game so that you do not make simple mistakes and do not underestimate an opponent. Everyone has a chance to win and lose a game. It is noteworthy that during tournaments it is improper to have discussions with players who are currently playing a game due to the level of distraction it brings. Staying focused simply helps you to keep your head in the game where it belongs.