Understanding by Jane Nelson was first published in 1986, then republished in 1996 with the title Understanding: Eliminating Stress and Finding Serenity in Life and Relationships. This book, although very simply written, triggered a major paradigm shift for me. I became a cognitive psychologist. That is, I realized that all thoughts arise from a belief system. I understood that a thought is just a thought until infused with energy by giving the thought sustained attention. I also understood from this book that no real and lasting psychotherapeutic change could occur unless there was a change in belief. I still have this precious book which has survived many geographical moves. I highly recommend Understanding which is available through Amazon.