This whole koan guessing game is a bit silly. The whole point of koans is that it takes long months of meditation and a very special frame of mind to understand them. If a guy reading a blog could guess the answer after five minutes' thought, the koan wouldn't be worthwhile anyway (I am willing to grant Eliezer his fox koan, but even he only solved part of that one, and only with the help of centuries of Western philosophy and deep personal knowledge of the issues involved).

But I will hazard a guess as to Annoyance's interpretation. Annoyance wants us to consider mundane experience more. The monk was hoping Joshu would teach him something really exciting about Buddha or enlightenment or meditation. Instead, Joshu reminded him that after you eat, you've got to do the dishes. The monk realized that Zen wasn't about fancy theories of ultimate holy reality, but about living mundane experience as fully as possible. He also realized that his thoughts of enlightenment were distracting him from a task he should be carrying out with his full mind, and when he concentrated his full mind on the present moment, he achieved enlightenment.

There are many places online where I can find koans. But I don't think a koan by itself is a topic I'm looking for on LessWrong.com, unless a poster is using it to make a particular point about rationality, a point which they explain as part of the content of the post. Plopping down a koan in front of us and expecting us all to figure out your point, or waste multiple people's time Googling when you could have simply linked to an interpretation, just isn't an optimally efficient transfer of rationality. It's not that it's bad, it's just not up to the standard of articles you've written or the general standards of LessWrong.com.

I don't think the definition of "obvious" you think is obvious is obvious.

At least, I think it's obvious it's not obvious it's obvious.

Even if koans like this have some legitimate insight buried in them, I wonder if the signal-to-noise ratio is too high to reliably extract that insight. Accurate, rational communication seems to be at least as hard as internal rationality.

I therefore propose an exercise of "reckless interpretation": Read the koan at a very surface level, then generate an arbitrary interpretation. Don't worry about it being too simple, too silly, or missing the point: The point is to miss the point. If these interpretations cannot be easily refuted with a technique other than "no, he meant it this way", then the koan is probably too ambiguous to serve as a useful communication device.

Here's mine for this one: Joshu is not teaching, he simply dislikes dirty dishes. The monk mistakes this for a legitimate insight, and by that unintended insight, the monk is enlightened.

Interesting, but for the sake of clarity or just to reduce inferential distance with the audience could you elaborate a little on the what it is you're getting at?

the flowering cherry
outside my office window
wasn't planted by birds

I suggest that in the future, posts like this should include a citation and/or link to the source. Surely you have one handy if you're reproducing it entirely?

I am particularly struck by those of you who point out that this koan is considered to be especially hard.

Yes, you're right, but I don't think you're appreciating what aspect of its interpretation is supposed to be difficult. The pattern that is being communicated is easy to understand. The challenge is determining what that pattern is meant to be applied to.

There are two relatively simple interpretations of that pattern, and one that is much less so. But that final interpretation is much harder for Zen students to perceive than for people who aren't. In fact, if you've grown up in a Western, English-speaking culture, I can virtually guarantee that you've been exposed to the third possible interpretation many times from multiple sources and in many different ways.