The quest for happiness has always been a fundamental human striving and meditating on ideal life is as old as philosophical thinking. Due to the knowledge and wisdom accumulated it can surely be stated that happiness is something that cannot be bought for money, or gained by power, and depends rather on how we interpret it than on external circumstances. Those who continually strive to get to know themselves, develop their personalities and learn to keep control of their subjective experiences are able to define the quality of their lives. As the well-known humanistic psychologist Rogers states: ¿¿ no matter with what problem people have turned to me, ultimately they always wanted to find the answer to the following questions ¿ ¿ Who am I? ¿ How can I become myself?¿ Developing our personality is of course beneficial not only for us. Both our immediate and wider environment can benefit from it in our private life as well as at work. The chapters and the tasks of the book were written in the hope of assisting readers in having a more complete, harmonious and happier life, and thus contributing to the achievement of our personal, organizational and social goals.