The last sentence in this quote has become quite famous as a way of navigating the inevitable ups and downs of this life:
All life is sorrowful; there is however an escape from sorrow; the escape is nirvana – which is a state of mind or consciousness, not a place somewhere, like heaven. It is right here, in the midst of the turmoil of life. It is the state you find when you are no longer driven to live by compelling desires, fears, and social commitments, when you have found your center of freedom and can act by choice out of that. Voluntary action out of this center is the action of the bodhisattvas – joyful participation in the sorrows of the world.
Joseph Campbell, The Power of Myth