The title of this book, Your Brain on Sex, is meant to catch your attention. Not just so you’ll pick up the book, but because of this: it is your attention to sex that can change your life. I don’t mean this in the ordinary sense of giving your sex life more attention. What I mean is that by focusing your thoughts on your true sexual desires, you can learn to understand what they mean and how you can use them to improve relationships, heal past wounds, and have a more fulfilling life. I use the word “brain” because what will be required of you is more than just physical or emotional. You will learn in this book how to think about sex intelligently so that your experience of it will organize your emotions, your body, your thoughts, your desires, your fantasies, and your spirit. Your Brain on Sex refers to what happens when all of these forces are engaged at full power. I call the process used to achieve this “intelligent lust.” Following the steps described in this book allows the brain to organize all the information you have about a sexual encounter into an experience that is more than just good sex. It is not only great sex, but also smart sex—sex that can change your life.