It only takes a moment to smile. It brightens up faces and lifts moods. It changes demeanors and curbs the harshness out of rebukes and reprimands. A smile uses less muscles - so quit giving your face such an extreme work-out. I like it when people's smiles reach their eyes. Then you know there is truly joy in their heart. You know they are happy. When it doesn't reach their eyes, there is a sadness that reaches to their heart. There is a grief they are trying to hide. You can try to cover up deep emotions but if your smile doesn't shine in your eyes, your eyes have belied your heart.