I used to think if you fell from grace it was more likely than not the result of one stupendous error, or else an unfortunate accident. I hadn't learned that it can happen so gradually you don't lose your stomach or hurt yourself in the landing. You don't necessarily sense the motion. I've found it takes at least two and generally three things to alter the course of a life: You slip the truth once, and then again, and one more time, and there you are, feeling for a moment, that it was sudden, your arrival at the bottom of the heap.

Source: A Map of the World (opening lines)