Look at the way Carter uses the dialogue between Matthew and Glory. In every exchange, you'll find the word not or don't or no or isn't or didn't. Why? What power does the negative hold in characterization, in dialogue, in real life?
Incidentally, I jumped out of an airplane once, in the height of my devil-may-care twenties. Glory asks, "What kind of a person would do that, and what do they get out of it, except a sense of relief when the thing opens correctly?" Well, I did not try heroin.