Dreaming is the closest I've gotten to testing myself against the challenge of maintaining rationality under brain damage.  So far, my trials have exhibited mixed results.

In one memorable dream a few years ago, I dreamed that the Wall Street Journal had published an article about "Eliezer Yudkowsky", but it wasn't me, it was a different "Eliezer Yudkowsky", and in the dream I wondered if I needed to write a letter to clarify this.  Then I realized I was dreaming within the dream... and worried to myself, still dreaming:  "But what if the Wall Street Journal really does have an article about an 'Eliezer Yudkowsky' who isn't me?"

But then I thought:  "Well, the probability that I would dream about a WSJ article like that, given that a WSJ article like that actually exists in this morning's paper, is the same as the probability that I would have such a dream, given that no such article is in this morning's paper.  So by Bayes's Theorem, the dream isn't evidence one way or the other.  Thus there's no point in trying to guess the answer now - I'll find out in the morning whether there's an article like that."  And, satisfied, my mind went back to ordinary sleep.

I find it fascinating that I was able to explicitly apply Bayes's Theorem in my sleep to correctly compute the 1:1 likelihood ratio, but my dreaming mind didn't notice the damaged prior - didn't notice that the prior probability of such a WSJ article was too low to justify raising the hypothesis to my attention.

At this point even I must concede that there is something to the complaint that, in real-world everyday life, Bayesians dispense too little advice about how to compute priors.  With a damaged intuition for the weight of evidence, my dreaming mind was able to explicitly compute a likelihood ratio and correct itself.  But with a damaged intuition for the prior probability, my mind didn't successfully check itself, or even notice a problem - didn't get as far as asking "But what is the prior probability?"

On July 20 I had an even more dramatic dream - sparking this essay - when I dreamed that I'd googled my own name and discovered that one of my OBLW articles had been translated into German and published, without permission but with attribution, in a special issue of the Journal of Applied Logic to commemorate the death of Richard Thaler (don't worry, he is in fact still alive)...