I think points 1-6 apply best to someone with an undergrad degree (and maybe even an undergrad degree in physics), since it's hard to grasp ie the action principle and Noether's theorem without having seen at least a bit of Newtonian and classical mechanics and E&M. Certainly my high school self would have struggled here.
I really like the idea of "depth first and work backwards" though. I finished undergrad with a degree in physics about a year ago, focused mostly on AMO, but since then I've seen all these headlines about AdS-CFT correspondence and cool quantum gravity papers and trying to read them is wayyy over my head. What I realized was that to read these papers, I needed to backtrack. I kinda needed to be familiar with some of the toy models for black holes in a quantum setting, which requires quantum field theory, which requires classical field theory, which I never got around to in school.
So now I'm reading a set of classical field theory notes and loving it! Plus I get to look forward to the eventual dig all the way back down to AdS-CFT.
I really like the idea of "depth first and work backwards" though. I finished undergrad with a degree in physics about a year ago, focused mostly on AMO, but since then I've seen all these headlines about AdS-CFT correspondence and cool quantum gravity papers and trying to read them is wayyy over my head. What I realized was that to read these papers, I needed to backtrack. I kinda needed to be familiar with some of the toy models for black holes in a quantum setting, which requires quantum field theory, which requires classical field theory, which I never got around to in school.
So now I'm reading a set of classical field theory notes and loving it! Plus I get to look forward to the eventual dig all the way back down to AdS-CFT.