A man in his thirties once jumped off from the Golden Gate Bridge to commit suicide. They later found a note in his back home that read: “‘I’m going to walk to the bridge. If at least one person smiles at me on the way, I will not jump.”
On the other hand there is also a story of Friedrich Nietzsche (1844-1900) who was once contemplating suicide during a particularly dark period. While he was lost in his despair, he was dissuaded from committing suicide by a smile from a total stranger.
There is a saying, “Give what you want to receive.” For example, if you want a smile then give a smile to others.
It says (Avos 1:15) והוי מקבל את כל האדם בסבר פנים יפות, receive everyone with a cheerful face. The Meiri (Avos 1:15) says that even if you are not happy to see him, make it appear as if you are happy to see him to the extent that he thinks you are happy to see him. (According to this explanation, the word סבר goes on the recipient, that he should think you are happy to see him.)
The first day Rebbetzin Jungreis arrived at the Bergen-Belsen concentration camp, her father turned to her and said, “Here you have a great mission.” She replied “Here? I’m just a little girl? What can I do here?” Her father answered, “Here you can give a smile to someone.”
Let us conclude with the following saying: “Let your smile change the world but don’t let the world change your smile.”