“I could be happier.”
How many of us have occasionally thought that?
While driving to work the other day, I did. And then I realized it’s not true.
I’ve done a few things of which I’m proud. There is more I want to do. And though Hashem has blessed me with almost everything truly important to me, there are still a few things I want.
But I couldn’t be happier.
In the Jewish tradition, happiness is most reliably found in life of justice: justice both external and internal, both in our actions and in our minds. It naturally includes reverence for God and respect for other people. It is guided by love. That agrees with the teachings of Jewish and Gentile sages throughout history. As Abraham Joshua Heschel observed:
"Judaism is concerned with the happiness of the individual as well as with the survival of the Jewish people, with the redemption of all men and with the will of one God. It claims, however, that happiness is contingent upon faithfulness to God ..." 
Rebbe Menachem Schneerson agreed:
”The only way to reach true happiness is through spiritual growth and achievement. And that means giving to others, loving and sharing, finding a deeper meaning in everything you do, and recognizing G-d in all your ways.” 
What if I got everything I wanted? Would that make me happier?
No. It would make me miserable. To be alive means to be striving, to be going somewhere, to have desires that are positive, fulfilling, and constructive. If I got everything I wanted, I wouldn’t be going anywhere. I wouldn’t be peering over the horizon, trying to do more than I had done and to become more than I had been. I’d be dead in the water. The only thing that could put wind in my sails would be some new wants, new goals, new reasons to move forward.
John Stuart Mill, the 19th-century philosopher and economist, knew it. Even though he was a great success, he reached a point in his early twenties when it all seemed meaningless:
"I put the question directly to myself: 'Suppose that all your objects in life were realized; that all the changes in institutions and opinions which you are looking forward to, could be completely effected at this very instant: would this be a great joy and happiness to you?' And an irrepressible self consciousness distinctly answered, ‘No!’ My heart sank within me: the whole foundation on which my life was constructed fell down. All my happiness was to have been found in the continual pursuit of this end. The end had ceased to charm, and how could there ever again be any interest in the means? I seemed to have nothing left to live for." 
Like all of us, Mill needed something he cared about to draw him forward. He gradually found his way again, first through poetry, then literature, and finally -- like many men -- through the love of a good woman.  He learned that happiness could not be found by brooding about our feelings, but by focusing on the good we can do:
”Ask yourself whether you are happy, and you cease to be so. The only chance is to treat, not happiness, but some end external to it, as the purpose of life. Let your self-consciousness, your scrutiny, your self-interrogation exhaust themselves on that; and you will inhale happiness with the air you breathe, without dwelling on it or thinking about it.” 
Or as Heschel said, taking a wider viewpoint:
”The world is torn by conflicts, by folly, by hatred. Our task is to cleanse, to illumine, to repair. Every deed is either a clash or an aid in the effort of redemption. Man is not one with God, not even with his true self. Our task is to bring eternity into time, to clear in the wilderness a way, to make plain in the desert a highway for God. ‘Happy is the man in whose heart are the highways.’ (Psalm 84:6).” 
Happiness is not found at the end of the highway. It’s found in the good we do while we are following the highway.
Heschel, A.J. (1976), God in Search of Man: A Philosophy of Judaism. New York: Farrar, Straus and Giroux.
Mill, J.S. (1873), Autobiography. Reprinted in Eliot, C., editor (1937), The Harvard Classics, Volume 25. New York: P.F. Collier & Son.
Jacobson, S. (2002), Toward a Meaningful Life: The Wisdom of the Rebbe Menachem Schneerson. New York: HarperCollins.
 Heschel, A.J. (1976), p. 349.
 Jacobson, S. (2002), p. 110.
 Mill, J.S. (1873), p. 86.
 Mill’s wife, Harriet Taylor Mill, was a remarkable woman. Some philosophers suspect she was the actual author of Mill’s best-known work, On Liberty, published under her husband’s name because his fame guaranteed an audience. Most likely, she also inspired Mill's energetic advocacy of equal rights for women.
 Mill, J.S., op cit, p. 91.
 Heschel, A.J., op cit, p. 357.