From the book 2666 by Roberto Bolaño:
Healthy people flee contact with the diseased. This rule applies to almost everyone. Hans Reiter was an exception. He feared neither the healthy nor the diseased. He never got bored. He was always eager to help and he greatly valued the notion – so vague, so malleable, so warped – of friendship. The diseased, anyway, are more interesting than the healthy. The words of the diseased, even those who can mange only a murmur, carry more weight than those of the healthy. Then, too, all healthy people will in the future know disease. That sense of time, ah, the diseased man’s sense of time, what treasure hidden in a desert cave. Then, too, the diseased truly bite, whereas the healthy pretend to bite but really only snap at the air. Then, too, then, too, then, too.