Like why I never got math.
True story: I learned the basics the old-fashioned way but as I began to get a firm grasp of it, this stuff was tossed at me, along with set theory (Feynmann has a great piece in this in his collected letters: he thought it was confusing and unhelpful). Then once I was good and confused — they switched back.
Gah. There’s a special place in Hell for educational theorists.