I'm returning to this a bit late. Sorry. I still think you're reading an implication that is not actually being made, and subsequently getting huffy about it.

I'm returning to this a bit late. Sorry. I still think you're reading an implication that is not actually being made, and subsequently getting huffy about it. I see no "clear implication" other than "this is not how those three things are most commonly learned currently". I cannot understand where it is that he is posing those three things against all other things.