At the risk of sounding fearfully reductionist, I propose that the stages to a fulfilled life are foolishness, wisdom, love, hope. Not linear of course, more a spiral. Regardless, many do not get past the first.
We all begin as fools. Children’s greatest asset and liability is their ability to be educated, resulting in spelling bee champs or child soldiers. It's just that many stay at a child’s level with respect to passively taking in information. All their lives they think in accordance with their institutions of learning then wage earning. They rarely question why they believe something; it is sufficient that the Jones do it. Their lives compose of eating baby food someone else already chewed up, or memorizing handouts someone else already made. Minds are enslaved. And if that alone is not enough to make you think this is the greatest human tragedy, it also is the thing (perhaps only matched by evil) that causes harm worldwide. To not think is like shopping at Walmart. The dollar saved comes at the cost of lives, environments, communities, workers' rights worldwide. And that "bargain" is only a placebo effect to which they have been taught equals happiness. The effect wears off almost immediately, so they go back again and again in the same futile search for satisfaction.
To move past this conditioned human condition, we must think for ourselves. To think is the thing that makes us human, expounded since Socrates: "The unexamined life is not worth living." Descartes: "I think, therefore I am." Solomon: "Joyful is the person who finds wisdom, the one who gains understanding. For wisdom is more profitable than silver, and her ways are better than gold." We need to train our own minds: to question the consequences of driving a Hummer on the Iraq War, snorting cocaine on Latin American drug violence, eating high fructose corn syrup on farm subsidies... Hence thought is not only the quintessential human quality, to know how evil exists is the precondition to preventing it.
But wisdom alone is insufficient to sustain us. A whole life is one that loves and is loved. As Fromm points out: "Even if we knew a thousand times more of ourselves, we would never reach bottom. We would still remain an enigma to ourselves, as our fellow man would remain an enigma to us. The only way of full knowledge lies in love: this act transcends thought, it transcends words." To have a passion, connect with humanity, do no harm, we must live with a heart that is open. When we are filled with frustration and anger, it is love that carries us through. Wisdom makes us see that our lives are bound up with our fellow beings’. Love calls us to fight for their lives as we would our own.
Yet as Woodstock showed, love is not the answer to all our problems. It requires hope to be sustained. To truly know and love a world that is broken in so many places brings heartbreak and despair. It then is near impossible to have your strength come from the same source that is causing you so much sadness. So how do we maintain hope? Gramsci writes while being a political prisoner: “To maintain the pessimism of the intellect and optimism of the will.” This optimism is more likely obtained if you believe in a moral code, an all-benevolent Being of truth and justice; not in the sense that you will be rewarded but that you are not alone in your fights and tribulations. It is the one that Thoreau wrote upon and Martin Luther King drew on in their works of civil disobedience. There is a "higher law" that decides whether man-made laws are just or unjust. There is a force greater than you, than this world that is on your side. In this comfort lies hope.
"And though I have the gift of prophecy, and understand all mysteries and all knowledge, and though I have all faith, so that I could remove mountains, but have not love, I am nothing. And though I bestow all my goods to feed the poor, and though I give my body to be burned, but have not love, it profits me nothing." 1 Corinthians 13:2.
