You probably have had it happen: you get that book on careers that everyone is talking about, get into it, then read something so blindingly obvious you stop. You ask why the author is wasting your time on stating something so incredibly obvious to anyone, and begin to question the book. Why waste your time with things you already know?
I've been there before. There's few books about business or careers I've read that haven't had some section that has made me wonder why the author is wasting my time with such things. Why tell me something I know – give me something I don't.