To learn quantum physics effectively during a gap year, it's crucial to establish a solid mathematical foundation, as undergraduate-level quantum mechanics requires advanced math skills. Recommended resources include Feynman's lecture series, particularly Volume 3, which covers probabilities and probability amplitudes in detail. Eugene Khutoryansky's YouTube videos are also beneficial for grasping basic concepts like spin and wavefunctions. For a more in-depth understanding, Griffith's textbook is highly recommended, along with MIT OpenCourseWare lecture notes. The learner's ultimate goal—whether to gain a superficial understanding or to achieve expertise comparable to a physics major—will significantly influence the approach taken. Building math skills in algebra, trigonometry, and calculus is essential for a deeper comprehension of quantum mechanics.