This piece looks great, adding to my ever-growing "to read" collection on Zotero.
If anyone is interested in self-studying quantum physics, QFT for the Gifted Amateur [1] is very well regarded.
See also, Atomic Physics for Everyone: An Introduction to Atomic Physics, Quantum Mechanics, and Precision Spectroscopy with No College-Level Prerequisites. - https://news.ycombinator.com/item?id=46961595
Second this book, but you need a source before this to study QP successfully. This requires a lot of UG maths and physics knowledge that I think most would not have.