It's good to uphold the rules
Andy is playing Tennis with Carl and the score has been very close in the game.
Andy wants to win the game.
Andy doesn't accept any points that are questionable and continues to play until both he and Carl agree that the game has been won within the rules.
Andy scores on his opponent but the ball appears to have hit the ground just outside the line and is out of bounds, but Andy insists on recording the point.
Both Andy and Carl feel good about the outcome of the game because there is no question about who won.
Carl is disappointed in Andy and Andy feels guilty about insisting on scoring a point that may not have been legal by the rules.