A series of videos explaining quantum mechanics, using math but with more emphasis on intuition than you will find in most textbooks. If you think you’re an idiot when it comes to learning these tough subjects, you might benefit by learning from me, a fellow idiot.
(Videos listed in reverse order of how they should be watched).
Topics covered in the Differential Equations playlist are orthogonal polynomials, Legendre and associated Legendre functions, Spherical harmonics, Bessel and Spherical functions, Laguerre and associated Laguerre polynomials, Hermite polynomials, and the Frobenius method. The videos that come after this point all assume you understand these concepts.