You probably do NOT lead a perfect life. Nobody does! How would you like to make your life much better? This book contains a few simple steps that can help you do just that by showing you How to Define Yourself. As you experience life, you are constantly bombarded with external stimuli which need your attention. How you respond to the stimuli determines how your life will turn out. Each response you make adds to your definition and that is how you Define Yourself. This book will help you understand the Stimulus-Space of Time-Response model which teaches that for each stimulus we receive, we have a very valuable "Space of Time" in which to choose our responses. It points out the importance of using that time wisely to choose good responses. As you do so, you are Defining Yourself. It also teaches you how to Predefine Yourself ahead of time, so responding to certain stimuli can be made easier because you have prepared for each response in advance. Similar to the way a parent or teacher would use flash cards to teach facts to a student, you can learn how to establish desired responses that you want to make for each stimulus you receive. Having a Predefinition of Yourself is great, but it does not count unless you actually use those desired responses when the corresponding stimuli are presented to you. The collection of actual responses you make is used to Define Yourself. Sometimes, you might get off course in life. Nobody is perfect, so we all have done so. However, this book will present the concept of Redefining Yourself as a means to make a mid-course correction as you live your life. It can strengthen your resolve to change your life for the better. And it can provide the inspiration for you to do so. The book is loaded with examples of real-life situations that implement principles. They are coupled with experiments which are suggestions of things you can do in your life to assist you as you Define Yourself. Even though the material covered by the book is quite complex, this book keeps the presentation simple so you can focus on what you need to know to Define Yourself and live a better life.