You know how sometimes you're talking to people who love you and give you unconditional love, and you say, "But you know what? Let me back up. I forgot to say . . ."You can do that, right? You don't hesitate and say, "Oh my God! I forgot to say that!". You just speak! And you say it all, until you have nothing more to say. And that's your first draft. It's done.
