"You see, but you do not observe..."

It is a running joke in the Holmes canon -- or, alternately, one of Holmes' pet peeves -- that other people wonder what he sees in the world, and he protests that he sees exactly what they do, he just makes something of it. You see, he says (especially to Watson), but you do not observe.

I'm generally less crabby about it, but his protest is largely true. People see a lot of things, every day, that they just don't treat as real observations. The thing goes into their brain, rattles around in there, and apparently hits nothing on its way back into the pile of unsorted sensory impressions. It's not even that people don't see what happens, although that's sometimes the case. They just don't ever think about why that happened, or how the world got this way.

I'm going to keep using Sherlock for examples. Aside from thinking that the cast is quite talented, that the writing is fantastic, and that clips are easy to come by on YouTube, I have this sneaking suspicion that my target audience has pretty much all seen it by now.

There is a brief scene in "The Hounds of Baskerville" where Sherlock, having just slammed into a wrong deduction face-first, finds something nagging at the corners of his thoughts. Being Sherlock, he rants for a bit at John and one of the Baskerville researchers before suddenly stopping and snapping, "Get out." The researcher lady is terribly confused, not having ever run into a Sherlock before, and John sort of chivvies her out, mumbling a sort of half-hearted explanation of what Sherlock is babbling about memory palaces. Sherlock spends quite a bit of time almost physically rummaging through the filing cabinets in the back of his brain, looking for something involving liberty and hounds -- the on-screen text that works so well goes flying all over here, and one of these days I'll go back and tell you all why I think it's so wonderfully evocative, but the point of this is the brief exchange above where he decides to go all Garbo and demand to be alone.

What you see is Sherlock ordering people out, and John sighing and clearing the room for him. Simple? Perhaps. Now for the observations. So: Break it down.

John is trying to explain to this poor woman what the hell is going on as he guides her out of the room. In order to explain things, you first have to know about them; this means that John has already seen this behavior.

("Memory palace", I should note, is Sherlock's phrase -- the mnemonic technique of constructing a space in which reminders are stored in a specific pattern is more usually spoken of as a memory house, with rooms that store categories of knowledge, or a memory walk or memory path, along which a sequence to be remembered is recorded as a series of sights or objects juxtaposed with mental landmarks. The palace part is a conceit of Sherlock's, and John obviously recognizes it when he says it.)

This means Sherlock has done this before, in front of John, without chucking him out of the room.

(Sherlock is pernickety about who gets to stand in the Immediate Braining Area when he's working; fond as he is of Mrs. Hudson, she natters, so she gets thrown out, and of course people he dislikes on principle get shouted out as quickly as possible. John seems to be immune to this. The editing makes it less obvious than it might have been, because of the POV change, but Sherlock is looking and pointing straight at the researcher when he barks his order -- John is effectively invisible. Sherlock's brain evidently does not class him as an irritant or interruption.)

(Is John aware that he is a permanent exception? Uncertain; this scene by itself does not provide enough information. He takes his accepted role of gatekeeper here. Elsewhere in the series it seems evident that he's picked up on it behaviorally, although it's still unclear whether he's consciously thought it through. Lestrade is also an acceptable gatekeeper, although John still has more permissions than he does.)

John not only knows what Sherlock is doing, but why and what the more normal basis is. Ergo, John must have paid enough attention while Sherlock was doing this before to have noticed it was a new strange thing, and to have asked for an explanation.

(Sherlock does an uncountable number of truly weird things pretty much every day. Chemistry in the kitchen. Heads in the refrigerator. Riding crops and corpses. It is not always immediately obvious what the hell is going on, and often people decide they are simply going to walk away and forget about it as quickly as possible. John adapts to most of them well -- head in the fridge excepted -- but he makes it a habit to respond to these things by asking WTF rather than just trying to block it out.)

Asking is no help if you get no answer. Sherlock must have actually bothered to give him a response.

(Sherlock explains bupkis to most people. He rambles irritably in run-on sentences, pointing at things and skipping over the boring bits he doesn't feel like repeating a thousand times. John is allowed, at times even encouraged, to talk, argue with and query Sherlock while he's thinking aloud. Sherlock indubitably enjoys the praise, but he also seems to enjoy the questions, to the point where when John asks where something came from, Sherlock doesn't monologue, he teaches -- complete with opportunities for John to work it out himself and praise when he does.)

(Also important are what John asks about. Other people demand Sherlock defend his deductions and assume that there simply isn't anything going on in his mind beyond that. John wants the reasons for pretty much everything unusual Sherlock does. Even when he's busy ranting and raving at his flatmate for not appearing to care that there are lives at stake, John asks the question about whether Sherlock realizes other people feel these things, and whether he does too.)

(Other people blithely assume that Sherlock has no emotional life at all. John's questions are predicated on the idea that he probably does, but it's not necessarily one he could guess at by looking. On Sherlock's end -- John is probably the only non-clinician who has ever wanted to know how he works. Even Mycroft doesn't show much of an interest in anything he can't use to manipulate his little brother.)

John manages to at least mumble out something the researcher can kind of follow. Which means that either he kept asking until Sherlock said something that made sense or pieced it together himself, and then John filed it away for later reference.

(Most people remember things about their friends, although much of it not consciously; most people also file these things away organically, through the course of conversations, and don't pay much mind to the process. John, in this respect, really does operate like most normal people do -- he absorbs things about Sherlock and generally assumes there's some kind of internal logic, which he will eventually figure out if his flatmate doesn't get him killed somehow first.)

(Sherlock also does it, although for Sherlock, this is highly unusual; he makes it a habit to ignore or delete things he thinks are of no importance, and in the past he's rarely if ever thought other people's feelings, when not tied to criminal motives, were of any interest. He tends to pause momentarily after John says something that's not immediately relevant to the case, or which he doesn't expect -- after he says he doesn't have to imagine what one might think the moment before death, after he tells Sherlock that the deductions are not obvious to others, whenever John tries to warn him it's not a good time to be gleeful about murder. It's a read/write blip. The information John has just given him is tangential to events but important for later, so he takes a moment to sock it away before getting back to the matter at hand. Sherlock does not forget these things: They add to the file of interesting things about his friend.)

To recap--

1. John has seen this before, which means
2. Sherlock has done it openly in front of him at some point;
3. John paid enough attention to ask about it, so
4. Sherlock explained, and
5. John remembered

To someone who is as who is as deeply invested in extrapolating from details as Sherlock is, these are not small things.

These are things which most people take for granted when they decide to become friends with someone, but as Sherlock is just learning how this works, he needs them -- data like this, and even data like his flatmate yelling things at him about people dying and how this was not what he expected from a trip to the circus with the nice lady doctor from the clinic, are things he needs in order to figure it out.