The importance of joy is so great that you should make every effort to be happy.
This can be compared to a group of people who are dancing in a circle while a sad person looks on. They reach out and pull him in to join them, whereupon he leaves his depression off to the side.
However, when the newcomer stops dancing, his depression returns.
Though the few minutes of joy are valuable, still, it would be better to bring the depression itself into the circle of happiness and keep it there (Likutei Moharan II: 23).
Forcing yourself to be happy will eventually turn the cause of your unhappiness into a real source of joy.
Chaim Kramer, Rebbe Nachman And YOU