The negative reviews are surprising to me. Griffiths's quantum mechanics is a spectacularly straightforward approach to a complicated subject matter, with troves of information. Problems are laid out to often give you *precisely* what you need to solve a problem (for example, there was even a reminder on how to complete the square to simplify the integral on one problem). Seems possibly mean to say, but if the math is too hard, you need more math. This is quantum mechanics, not introductory Newtonian mechanics.