Do you want to remain in control of your life always? You must understand your needs and the way you fulfill them, since these define your behavior and therefore your life. However, needs are not random and individual as they may seem, but they form entire hierarchies to span your mind and body, defining continuously your feelings and cognition. If you remain unaware of this entire cognitive process you are never able to understand and control yourself, while your life will always surprise you and remain unmanageable. …And if this is not enough, others can find ways to control you by sending you their artificial hierarchies of needs, you fulfill these as your own, you end up serving others while harming yourself and your loved ones, and you call this life and existence. What is natural and what is artificial in your life? What is good and what is bad? What is valid and what is irrelevant? You will never know it unless you can identify and understand your own, natural needs and hierarchies of needs. What we are seeking throughout this book is to understand all needs and hierarchies of needs, by modeling and classifying them accurately, helping you acknowledge, predict, and manage everything at will, in order for you to be able to discern what is good, useful, necessary, and prioritized in life and in the world. This particular study of the hierarchy of your needs does not only span your entire life and behavior on all their distinct levels and classes, but it allows you to develop and remain aware of your reasoning, since the level of your reasoning itself must match precisely each level and perspective of each need and fulfillment modeled and classified here. This is why, for a better understanding, I integrate this study within the entire cognitive system, while making further correlations to adjacent topics and systems as the human body and mind, the human development, society, civilization, natural laws of the universe, existence, and life. If you want to learn more about yourself and the world, if you want to understand the multitude of needs and feelings spanning your life, if you want to understand and manage your life and behavior, then this book is for you!