Your face is not just your business. It is public property. You only have to look at your own face once briefly in the morning. Everyone else has to look at your face all day. So just because you are in a bad mood or going through a rough patch, doesn’t mean everyone else has to be brought down too. The people around you deserve to be greeted with a pleasant face.
Of course, smiling is not only for the benefit of others, but for your own benefit too. The number one cause of misery is not life’s troubles but rather self-absorption. The more you think about yourself and your predicament, the more you marinate in self-pity, the more miserable you become.
On the other hand, when you look outside of yourself, look around you and see how you can be of service to others, when you smile not because you are in the mood but because others deserve to be smiled at, you start to feel upbeat and light again.
This is not to say that there are never any real reasons to be sad, or that smiling is a magical cure for depression. The point is that smiling is a duty you have to others. And when you focus on your duties rather than your difficulties, you are on the road to happiness.
So Smile 🙂
Menachem Mendel Bluming, Rabbi Moss and Chabad.org