I should add the disclaimer that by nature I'm an apologist for pretty much any fiction I read, and HPMOR is quite haloed for me on top of that.

That said, I thought that having several chapters of exposition where Harry gets to ask all the questions he's been wondering, followed by a whirlwind of utter bewilderment as Quirrell pulls a warren from the woodwork, was a successful demonstration of the challenge of "The enemy is smart."