Until reading this, I had never considered reading a 'motivational' or 'self help' book, especially as most of them are of the American Genre of 'hot coal walkers'. However, with some time on my hands and a slightly dented confidence after losing my job, I read this book eleven years ago and was very impressed. Of course, in the end its just a book, not the Holy Grail for all life's problems, but it is a useful tool for helping you to examine exactly how you behave, why you behave like you do, what you are about and how this knowledge effects your attitude, life choices and future success in whatever you do.
None of these books will 'change your life' without real effort on your part, and certainly not all of what these authors have to say is without room for criticism, but this book of simple and practical 'life truths' certainly motivated me and gave me another perspective on things. Looking back, the book did change my life's direction in subtle but very important ways and helped to give me the confidence to do what I wanted to do. Of course, succeeding at it still takes courage, knowledge, effort, persistence and a bit of luck!
Another book I'd thoroughly recommend is Stephen Covey's 'The Seven Habits of Highly Effective People'. This is much more a philosophical mishmash of 'common sense' things that most of us never actually implement! If you are looking for some quick fix solution to help your sales technique or bank balance, there are other books that are better suited to your needs. But if you are trying to clarify what you really want and how best to achieve it (whilst remaining a balanced and pleasant individual) then these two books are worth reading, and reading again.
Definitely worth investing a few quid and some time.