Everyone wants to be "happy," but is happiness enough? It's not.
We go to simchas; we wish each other "chag sameach"; but do we really understand the profound meaning of living in a steady state of joy? How is simchah different from - and far superior to - the more fleeting and elusive emotion of happiness? How can one have simchah even during times of sadness and even mourning? How is simchah cultivated through our holiday celebrations, through such practical mitzvos as tefillin, mezuzah, the laws of family purity, and through such significant rites of passage as bris milah, pidyon haben, and more?