To break up the awkward silence at the start of a recent Overcoming Bias meetup, I asked everyone present to tell their rationalist origin story - a key event or fact that played a role in their first beginning to aspire to rationality. This worked surprisingly well (and I would recommend it for future meetups).
I think I've already told enough of my own origin story on Overcoming Bias: how I was digging in my parents' yard as a kid and found a tarnished silver amulet inscribed with Bayes's Theorem, and how I wore it to bed that night and dreamed of a woman in white, holding an ancient leather-bound book called Judgment Under Uncertainty: Heuristics and Biases (eds. D. Kahneman, P. Slovic, and A. Tversky, 1982)... but there's no need to go into that again.
So, seriously... how did you originally go down that road?
Added: For some odd reason, many of the commenters here seem to have had a single experience in common - namely, at some point, encountering Overcoming Bias... But I'm especially interested in what it takes to get the transition started - crossing the first divide. This would be very valuable knowledge if it can be generalized. If that did happen at OB, please try to specify what was the crucial "Aha!" insight (down to the specific post if possible).
We need some kind of word that means "seeker after less wrongness", and refers pragmatically to a group of people who go around discussing epistemic hygiene and actually worrying about how to think and whether their beliefs are correct. I know of no shorter and clearer alternative than "rationalist". There are some words I'm willing to try to rescue, and this is one of them.
Perhaps it's not worth complaining, but historically "rationalist" was contrasted with "empiricist." Descartes, Leibniz, and Spinoza were rationalists, while Locke and Hume were empiricists. Obviously that's not a contrast you mean to be invoking, though maybe that use of "rationalist" is rare enough that there's no risk of confusion.