Mankind had come so far in some ways, and in others remained up in the trees, chittering and throwing rocks at each other. If only the trees weren’t … - Larry Niven

Long ago, Louis Wu had stood at the void edge of Mount Lookitthat. The Long Fall River, on that world, ends in the tallest waterfall in known space. Louis's eyes had followed it down as far as they could penetrate the void mist. The featureless white of the void itself had grasped at his mind, and Louis Wu, half hypnotized, had sworn to live forever. How else could he see all there was to see?
Now he reaffirmed that decision.

Writing is, therefore, both a form of compulsive behavior and, I frequently tell people, a self-induced form of mental illness. Those few writers who don’t start off by being a little nuts soon get that way as a direct result of their vocation.

Somehow, Nessus managed to function. He found it hard to care.