I think it's reps.

I realized, a few years ago, that without ever intending to, I'd been training for years: writing in a journal, digging into things, trying to understand them, and part of understanding them was asking questions, trying to go back to the very root of whatever it was so at least I'd know what I didn't know. And since it was just me, staring at a notebook, I could afford to be really stupid. Like, who cares if I reveal, in my notebook, what a dunce I am, how I don't understand the basic things about x?

I think that was it. I just got in the habit of doing that, and after thousands of hours of it, it began to pay off when I got in an honest environment that valued truth-seeking. Probably the second part should be emphasized more -- it's a rare environment where trying to get at the truth is rewarded. I wound up in one by accident.