The idea that excites me the most concerns the two greatest puzzles in science: the origin of the universe, and the origin of consciousness. The origin of the universe is what I do for a living, working on string theory. But I am also fascinated by consciousness.
[. . . ] I suppose this was the first time I had ever felt an urge not to be. Never an urge to die, far less an urge to put an end to myself - simply an urge not to be. This disgusting, hostile and unlovely world was not made for me, nor I for it. It was alien to me and I to it.