It was mostly just a recommendation to check out. I did not actually do it myself, but I tend to think I could have right after lin.alg./multivar calc freshman year and would have preferred it. Can't prove that, of course, since I didn't do it, but a year later I was loving Landau's Classical Theory of Fields which has a very similar relativity-first approach, and I did know a lot of relativity in high school. Wolfram went right from high school to grad school in physics at Caltech. The only very recently deceased late great Ed Fredkin got to be head of the MIT CS department with naught but a high school degree due to various life interventions and had some interesting "digital physics" ideas.
There are lots of pathways to learn & do. That is especially true of people coming to topics later in life, as I might expect is more common for HN comment thread readers. I know someone who learned to program in x86 assembly before they learned C (in fact one of the best programmers I know). If you talk to such people, I think you will find that their more varied backgrounds / ages in life when they approach things make anyone's dogmas more suspect. A great numerical relativist didn't study physics until his 30s. No idea what order he did things in, but I heard it was very non-standard.
So, I would encourage you to have more imagination of what might be possible / be less dismissive / jumping to conclusions. That is needlessly discouraging to many here were bemoaning "soooo many books/years/etc". "Ambition" might be "first learn diffgeo, then learn physics". I've been recommending that lately to a friend with extreme mathematical sophistication (a professor even) but no physics exposure, actually, but already some diffgeo exposure.
And, of course, "to learn physics" is maybe not to be a "produced physicist" any more than "to learn networks" means to "build a hardware router". It all depends. IMO, there are too many levels (& even directions/dimensions) of "having learned" to really even make "just can't", "only way" statements like you did. Elsethread, the diversity of even what "physicists" wind up having learned is shown to vary considerably (e.g. continuum mechanics). I find such absolutist statements needlessly discouraging to someone who might be hopeful to do it in "fewer steps". The way for most need not be the way for all or even the recommended way for any one person. People vary.
There are lots of pathways to learn & do. That is especially true of people coming to topics later in life, as I might expect is more common for HN comment thread readers. I know someone who learned to program in x86 assembly before they learned C (in fact one of the best programmers I know). If you talk to such people, I think you will find that their more varied backgrounds / ages in life when they approach things make anyone's dogmas more suspect. A great numerical relativist didn't study physics until his 30s. No idea what order he did things in, but I heard it was very non-standard.
So, I would encourage you to have more imagination of what might be possible / be less dismissive / jumping to conclusions. That is needlessly discouraging to many here were bemoaning "soooo many books/years/etc". "Ambition" might be "first learn diffgeo, then learn physics". I've been recommending that lately to a friend with extreme mathematical sophistication (a professor even) but no physics exposure, actually, but already some diffgeo exposure.
And, of course, "to learn physics" is maybe not to be a "produced physicist" any more than "to learn networks" means to "build a hardware router". It all depends. IMO, there are too many levels (& even directions/dimensions) of "having learned" to really even make "just can't", "only way" statements like you did. Elsethread, the diversity of even what "physicists" wind up having learned is shown to vary considerably (e.g. continuum mechanics). I find such absolutist statements needlessly discouraging to someone who might be hopeful to do it in "fewer steps". The way for most need not be the way for all or even the recommended way for any one person. People vary.