I am not sad.

"He awoke each morning with the desire to do right, to be a good and meaningful person, to be, as simple as it sounded and as impossible as it actually was, happy. And during the course of each day his heart would descend from his chest into his stomach. By early afternoon he was overcome by the feeling that nothing was right, or nothing was right for him, and by the desire to be alone. By evening he was fulfilled: alone in the magnitude of his grief, alone in his aimless guilt, alone even in his loneliness. I am not sad, he would repeat to himself over and over. I am not sad. I am not sad. Because his life had unlimited potential for hapiness, insofar as it was an empty white room. He would fall asleep with his heart at the foot of his bed, like some domesticated animal that was no part of him at all. And each morning he would wake with it again in the cupboard of his rib cage, having become a little weaker, but still pumping. And by midafternoon he was again overcome with the desire to be somewhere else, someone else, someone else somewhere else. I am not sad."

From Everything Is Illuminated by Jonathan Safran Foer.