It seems everyone's been aiming at the same meta-level, so I thought I'd try something a bit less direct.
The quote, for me, comments on several common themes around here. Probably the strongest connections I make are to updating of priors based on evidence, and to the issue of communication, when the speakers possess different levels of self awareness and rational thinking ability.
The image is also one of the most recognizable from the book, and I thought it's worth while having it referenced here - though I suppose I should have researched a less oblique quote.
I can guess at what you're getting at, but it's not really a sufficient quote to support the conclusions. If Don Quixote is good reading on the matter of rationality, that's all to the good, but I can't see it in just these five lines.
(Last month's started a little late, I thought I'd bring it back to its original schedule.)
A monthly thread for posting any interesting rationality-related quotes you've seen recently on the Internet, or had stored in your quotesfile for ages.