“As a young dancer, when approaching a step or lift or turn I deemed hard, I would say to myself, Don’t [expletive] this up. … At times I wondered if it was a form of superstition, that the very act of thinking Don’t [expletive] this up would protect me from any and all regrettable mistakes. But I had come to realize that the common thread among the disparate artists I admire most is that they do not protect themselves at all.” An excerpt from his new memoir.