Ooops, oh no! After 40 years of using Emacs I missed about 1/3 of the shortcuts on Emacs Beginner's Cheat Sheet (linked on Sacha's (@sachac) always excellent Emacs newsletter): https://www.reddit.com/r/emacs/comments/zi9gea/ultimate_emacs_cheat_sheet/
I think it is true that for most of us, we learn what we need to get done what we want to get done and then stop learning.
That is why I enjoy writing so much. When I start writing a new book I have preconceived notions (often incorrect) that I already really understand a subject.