A couple of years ago, I tried to explain to Eric that he had a bad conversational habit. When Person A brings what she thinks is a new item into the conversation, and Person B says "Oh yeah, I already know all about that," Person A feels as though her conversational effort has been rebuffed or she's being called stupid for thinking the item is new or interesting. I used the Gricean maxims, specifically quantity, to explain to Eric why his habit bothered me: he was acting as though I had broken the "be informative" rule.

Patrick Nielsen Hayden is a little more forthright and antagonistic when he sees this habit:

I personally think conversations about the current emergency would be vastly improved by a general moratorium on the "What, You Just Figured That Out, Where Have You Been?" rhetorical gambit. Indeed, what that particular routine indicates most clearly is that the speaker is more interested in striking a pose than in actually forming a useful alliance.

...

"Charles Dodgson": "I must be a more cynical SOB than Patrick --- I'm not remotely surprised. It's just a fact of human nature that [etc]"

I like your writing and I like you, but this is an online rhetorical gambit on which I call BS.

First, point to where I said I was surprised.

Second, the game of "You're surprised by $ODIOUSBEHAVIOR???" is itself odious. Hello, person who has, by dint of great effort, worked themselves around to agreeing with me! Allow me to point out in the most withering possible terms that I'm more worldly than you, more knowledgeable than you, more sophisticated than you, and boy howdy, are you ever a chump.

I've indulged in this variety of superiority dance myself. Astonishingly, it turns out to not be the most effective imaginable way of acquiring and retaining allies. Human nature is so unpredictable; who could have known?

Last night I saw Eric and a bunch of other folks in my master's cohort at Jen's party. The Swiss guy played the piano and I joked that the hydrazine in that satellite the government's shooting down is just a Xeroxed zine for people who love water -- perfectly harmless! I mentioned how much I love my new job, especially because the people are friendly: more specifically, the founders at the top don't shun human interaction the way Joel and Michael do, and the company culture suits me far better. Sure I'll have moments of conflict with my coworkers, but they'll be about "who's in charge of this task" or "you should have done that more quickly," not a fundamental misapprehension of human nature.