I purchased this book after reading about 50 positive reviews here on Amazon, still unconvinced that a book would undo 15 years of smoking. Well, I followed the instructions, and here I am: a non-smoker of 6 weeks. I must admit, you probably will have to want to quit smoking to accomplish this feat, but aside from having the desire, Allen Carr takes care of the rest. I am not sure how it works; it is my theory that the author hypnotizes the smoker into being a non-smoker through repetition. No matter how it works, I can breathe, and my fiance was pleasantly surprised with my dedication to non-smoking.Give this book a try. You won't regret it.