This book plus the others contained within is fantastic. It's not really about codependency, per se. It's really more about learning what relationships should be based on, and what they should not. One of the biggest takeaways I learned from this book is that a good relationship cannot come from having similar bad experiences. A good relationship is built on two people's best sides connecting and trying to bring out the best in one another. Not their "bad sides" or past hurts and trauma bringing them together. Fantastic read, I recommend it to anyone who has ever gotten to the end of the relationship and wondered what went wrong.