If your still alive your mission on earth is not yet complete. People are happiest when they are so completely engrossed in an activity that they lose track of time and go into what is called a flow state. For this to occur, the activity must be reasonably challenging, neither too easy or too hard. It must be something that is of value to others, and it must be something that you love, that you can be passionate about. Your passion for your work will get you out of bed and into the workplace' even when you don't really feel like it, even when you are discouraged about your progress.
When selfishness vanishes, all you want from life is to give. It is a constant source of joy. Not that you are blind to sorrow. Personal suffering is gone, but for that very reason there is no barrier separating you from the suffering of others. And that immense empathy releases intense action. "What one takes in by contemplation," Eckhart says, "one pours out in love." You live to give, to alleviate the sorrow and improve the lives of those around you, and in that giving is more joy than the world knows. It is the perfect fusion of the inward and outward currents of life, of meditation and action.