What “Mel” did was take “You cannot control the behavior of others, but you can always choose how you respond to it” quote from Roy Bennett and called it Let them theory. She does not provide any insight on how to deal with the heartbreak, sadness, hurt of rejection which cannot be explained by simply saying “Let them”
There is nothing useful in this book. She sounds like the annoying friend who knows it all and wants to tell you how to live your life. This book is self serving at best.
Robbins talks about research for the book and “all the experts” but does not provide citations nor actual research. In one of the chapters she says that if your parents are paying for your therapy they have the right to talk to your therapist. Talk about breach of confidentiality!
Save yourself money and time and say Let me not read this