Dear Eliezer Yudkowsky,
I wish to sincerely thank you for the works that you have written and published, most especially your magnificent work of fanfiction, Harry Potter and the Methods of Rationality. It is an enjoyable and engrossing story, and my wife and I found happiness reading and discussing it together.
But that’s not really why you wrote that story, is it? Entertainment is all well and good, but what you really want is to educate people, so that we can actually know and apply those methods of rationality you mentioned. Well, it so happens that your book worked; I did learn something from Harry’s adventures, and I used it to improve my own life.
Earlier this year, I went down to Nogales (the Mexican half) with a friend, on a mission. I was there to have a good time being a tourist, and also to obtain six bottles of Mexican vanilla (my wife wanted some for herself and some to share with family and friends). I had brought with me 20 American dollars. My wife assured me that this would be enough to cover any expenses I would encounter.
Well, as my friend parked his car in Nogales (the American half) and we approached the border, I thought about that money, and wondered if it would be enough, and I remembered Chapter 6: The Planning Fallacy when Harry gives that little lecture about being sufficiently pessimistic and reveals the gold he secretly swiped from his vault. I decided that I, too, wanted to have enough money to buy what I really wanted, and withdrew 40 more dollars from the nearest ATM. I then followed my friend to the moneychanger’s office, where we converted our dollars to pesos, and we crossed the border.
I spent every last centavo, and it was great.
I bought some chocolate in brand names that I’d never seen before. I had a strange and lovely meal in a very authentic hole-in-the-wall restaurant. I bought a locally-knitted jacket for my daughter, and I probably overpaid because I have no experience bargaining, but I could afford the loss. I bought a little silver bracelet for my wife. And I bought six of the largest vanilla bottles I could find. My trip was a complete success.
So, Mr. Yudkowsky, if you ever lie awake at night, wondering if you’ve ever actually succeeded at helping anyone be more rational, remember that you helped me, at least a little. Even now, there sits in our kitchen a vanilla bottle as long as my forearm, and it wouldn’t have been half as big if not for you.
Thank you again, and good luck to you,