I would like to recommend the book
Switching Power Supply Design (Pressman et al), which I recently came across when wanting to learn a bit more about SMPS, triggers by a repair project.
I had a read of the chapter about the flyback topology, and it immediately let me see through the essence of it, which was extremely satisfying.
Then I read the Preface written by its second author, with amusement. A read of it is recommended to all.
Perhaps, if there is enough interest and like-minded people here, we can let this thread grow as a readers' club of this book, to exchange ideas, questions, insights, etc.