I wanted to read this book because I had done a lot of mental prayer, but I didn't really know the rules or best practices. I just sort of sat down at adoration and thought about my life, God, and the mysteries of the rosary. I knew from a different book on eucharistic adoration that it's generally good to do several types of prayer: thanksgiving, adoration, supplication, and repentance. Beyond that I knew nothing. This book really helps you solidify some of the methodologies to keep in mind, and it explains the logic and reasoning behind each. Basically, this book is going to give you a firm foundation of principles to rely on for mental prayer moving forward.