Fitzpatrick's online graduate course in quantum mechanics is compared to Feynman's lectures and Sakurai's textbook, highlighting significant differences in difficulty. Feynman's lectures are designed for first-year university students and aim to foster a love for physics, making them less challenging than advanced texts. In contrast, Sakurai's book is recognized as a difficult graduate-level resource. Fitzpatrick's course is positioned as being more aligned with Sakurai's complexity, suggesting that it is intended for a more advanced audience. Overall, the consensus is that Sakurai is considerably more challenging than Feynman's introductory approach.