A point that's rightfully emphasized by the author:
> Solving problems is the only way to understand physics. There's no way around it.
This generalizes well to other fields. I don't want to discourage anybody from trying to educate themselves in a difficult field (be it physics or something else), but that's a very common and immediately visible problem with autodidacts. If you haven't worked through enough hard problems you lack the intuition that ties together theory.
> Solving problems is the only way to understand physics. There's no way around it.
This generalizes well to other fields. I don't want to discourage anybody from trying to educate themselves in a difficult field (be it physics or something else), but that's a very common and immediately visible problem with autodidacts. If you haven't worked through enough hard problems you lack the intuition that ties together theory.