A Nice Guy, according to certified marriage and family therapist Dr. Robert Glover, is a man who believes he is not okay just as he is. He is convinced that he must become what he thinks others want in order to be liked, loved, and get his needs met. He also believes that he must hide anything about himself that might trigger a negative response in others.
This inauthentic, chameleon-like approach to life causes Nice Guys to feel frustrated, confused, and resentful. Subsequently, these men are often anything but nice. Common Nice Guy patterns include giving to get, difficulty setting boundaries, dishonesty, codependency, people-pleasing, conflict avoidance, passive-aggressiveness, unsatisfying relationships, and sexual issues.

With this book, Dr. Glover has guided hundreds of thousands of men through the process of recovering from Nice Guy Syndrome. These readers have learned how to release toxic shame, soothe their anxiety, face their fears, connect with other men, embrace their passion and purpose, and experience success in work and career. These men have also learned to set boundaries, handle conflict, make their needs a priority, develop satisfying relationships, and experience great sex. 

No More Mr. Nice Guy does not teach men how to be not nice. Instead, Dr. Glover shows men how to accept all aspects of themselves: their power, humor, courage, and purpose, as well as their fears, imperfections, mistakes, and rough edges.