I am an undergraduate senior and was having trouble with QM, and was thinking of giving up QM, but I found this book and I went from being confused and totally lost in QM to being able to even read farther topics like Scattering theory. For example the book written by David Griffiths is very well written too, but it doesn't provide you answers to the question, it isn't rigorous and it doesn't provide as much information as you need for self-study, but this book does have answers to solved problems, it is rigorous and it provides enough information for self study that it feels easy to understand the subject itself. If you have an instructor David Griffiths would be as good, but if it is self study, this book is definitely better!<br> Also this book doesn't only explain about the subjects but have many examples, solved problems and exercises that you would never get lost as long as you keep doing them!<br> I personally think this book covers more than enough topics in QM that you can go to the next step like Quantum Field Theory afterward. So if you get lost in QM but need it, this book is your best shot!