I can't help but get the feeling that most bad reviews here are from people who are frustrated with the difficulty of the problems in this book.<br><br>I was initially shocked by the amount of insights contained in every section! Throughout this book, the author presents various helpful examples with proper commentary. He points out the subtle points and he always shares his -at many instances, unique- insights. He is very verbose but everything he mentions is great and very beneficial for the reader!<br>After Dr. Morin has provided the reader with the proper background to solve the exercises (without ever rushing it), he proceeds to solved exercises. There are lots of them in each chapter (about 20-30 each chapter). After this, the author provides the reader with a lot of unsolved exercises for him to solve alone.<br>So, we now come back to the first sentence of this review. Many complain that the problems are diabolically difficult. Well, after so many worked out examples, I think that having difficult problems (with solutions of course) is a natural extension. The reader starts solving easy exercises, and they gradually get more difficult. Moreover, the problems are themselves very interesting and quite a few of them require creative thinking, which is amazing!<br>Furthermore, for the reviewers who found that the exercises were too difficult, it is not expected by every reader to be able to solve the more difficult exercises. This is a book for everyone: from dumb people to really smart; it's just that the smarter you are, the more exercises you can solve, which is only natural. Mediocre students can skip the various insights and just go over the solved problems and refer to the solutions when they can't solve them. Anybody at a higher level than them can appreciate the insights, try to solve the solved problems and then proceed to the unsolved ones. Of course, as I said, you can't expect to solve everything because some exercises are for the really smart reader. But, it's safe to say that anyone who sticks with this book, no matter what his/her level is, is going to learn a lot about the concepts described here and learn how to solve much more difficult exercises than they thought they would be able to solve. Not being able to solve all of them is only natural for a book that does not assume that its reader is dumb.<br><br>For me, insightful books like this should be in every physicist's bookshelf.