These apparently simple attempts to communicate what you’ve learned, to yourself or others, are not merely a form of self-testing, in the conventional sense, but studying—the high-octane kind, 20 to 30 percent more powerful than if you continued sitting on your butt, staring at that outline. Better yet, those exercises will dispel the fluency illusion. They’ll expose what you don’t know, where you’re confused, what you’ve forgotten—and fast. That’s ignorance of the best kind.
