There are a lot of things Sherlock won't admit to having 'deleted' from his brain. Sometimes John can catch him off guard with it; trap him into coming clean about some mundane thing he'd made himself forget and then exploit at his expense. It's fun, as it both flusters and frustrates him, but it's like he always says; it's not like he doesn't realize these things (of course he knows about all that 'thirty days hath September' business; it's just sometimes those last lines about February living under special circumstances escape him)- it's just that he has more important things to remember.

John knows he can't blame him for that. He understands how stressful Sherlock's line of work can get without him having to try and remember that the sky isn't inherently blue all the time.

But it's when Sherlock starts to display signs showing that he's having trouble seeing through his own hair does John begin to wonder whether or not the man's forgotten that hair grows.

He first begins to notice it when he walks into the lab one day and sees Sherlock hovering over a microscope. He goes to stand by his side (in case Sherlock decides he needs something nearby), and stands idle for a moment before noticing Sherlock is acting oddly.

The detective isn't as calm as he usually is whilst working, but he's not making scenes like he does when he becomes stressed, either. It's something else entirely, but John can't place what it might be right off the bat.

He stands studying the detective for a moment before it suddenly comes to him: Sherlock keeps interrupting himself.

He has to stop gazing through the lens periodically to brush his hair out of the way, letting out little grunts of annoyance each time he does. He finds he can't hold back his laugh at that and Sherlock turns on him and demands he leave the room so that he can have total concentration. He obliges, but not without ruffling the taller man's hair first. Sherlock gives him an odd look as he leaves but forgets about it a moment later as he resumes his work.

It happens again a few weeks later, though this time they're in the middle of a case. They're busy frantically looking through all the various documents Sherlock has splayed out for information when John hears those huffs of irritation again. He pauses in rifling through the documents in hand to glance at Sherlock to see that the man seems to be having trouble keeping his hair out of his eyes long enough to read anything. The stress of the situation momentarily dissipates as he watches the way Sherlock busily tries to keep his shaggy curls from dipping into his line of vision, repeatedly brushing them away and attempting to tuck them behind his ear, but to no avail. Frustrated when they just keep falling back into his eyes, he angrily looks about for something to keep them contained when he catches sight of John watching him.

"Well?" he snaps as he searches about for something suitable enough to keep his hair at bay. "Have you found anything yet?"

"Hair tie for your thoughts?" John quips as Sherlock snarls, but his expression quickly lights up. John can hear him mutter 'yes, hair-tie, of course' under his breath as he passes by on his way into his room.

John resumes his search and only stops again to bark out a quick laugh when Sherlock re-emerges with a necktie wrapped around his head.

"That's not what I meant." He says as he laughs, but Sherlock ignores him in favour of focusing on the work at hand.

Only when the case is done and their form of normalcy returns does John think to bring it up, knowing full well that Sherlock, when engaged in detective work, was prone to blowing off anything he had to say that didn't pertain to what he was doing at the moment.

"Sherlock, surely you've become aware by now that your hair is not self-maintaining?" John queries one afternoon as he watches Sherlock struggle to put a pair of safety goggles on that doesn't trap his hair in with his eyes.

John sits in the main room with his laptop in his lap, typing up a collection of his thoughts on this whole hair affair as Sherlock busily struggles with the goggles in the kitchen.

"What?" Looking up from his current experiment, Sherlock spares John a quick glance before giving up on the goggles and casting them aside. "Don't call me Shirley, John; nick-names are unbecoming."

John snorts and makes a note to add that into his entry; 'Sherlock takes after Leslie Nielson in Airplane!'.

"I wasn't, you git. I was asking if you were aware that you look like a shaggy dog."

"Well, that was rude. There's nothing remotely canine about me, save for the designated teeth." He says as he shakes his head to try and clear his hair away.

"Oh come on, surely you've noticed-"

"-Don't call me Shirley." He interrupts seamlessly.

"…Noticed your hair's gotten a bit overgrown." John says around a hint of irritation. " You look like you could pass for a Ramone."

Sherlock ignores his last comment and instead turns to focus on whatever it is he's brewing in the tubes on their table. John watches him work briefly, mulling things over in his mind before turning all his attention back to typing.

Things become as quiet and peaceful as they come in the flat as each occupant busies himself for a time; but such lulls in excitement only last for so long in their world. It doesn't take long before Sherlock starts to make a fuss, handling his test-tubes rougher than he ought to as his agitation grows. John looks away from his laptop for a moment to see what Sherlock's doing, and watches as the poor man tussles his hair around angrily in distress. John sighs, realizing something has to be done before Sherlock tries to burn his hair away with whatever dangerous chemicals he's handling and shuts his computer, turning in his seat to call out to him.

"Sherlock."

"What is it?" comes his immediate reply, snapped in a brusque and angry tone. "Can't you see I'm busy?"

"Oh, yes, I can see just fine; it's you I'm having concerns with, regarding sight."

"I have 20/20 vision, John. There's nothing wrong with my sight." He says, enunciating sharply.

It's as if Sherlock can't register the fact that it's the length of his hair that's causing him all this trouble. Cleary he understands something's off, but he doesn't seem to understand that the issue is hanging quite literally in front of him.

John sighs and rubs at his forehead.

"Sherlock, there's no easy way to say this…"

"Well, get on with it. I'm quite busy at the moment, as I'm sure you can see."

"You need a haircut." John says flatly, staring at him pointedly when Sherlock turns to him with a scoff, momentarily abandoning his lengthy locks.

"A what?"

"A haircut, Sherlock. Surely you've not deleted that from that great idiotic brain of yours."

"I told you not to call me Shirley," He says, and, if John could have seen them, rolls his eyes. "Forgive me if I'm a little skeptical about your hair related theories after you suggested a, what was it, 'hair-tie'? Lestrade's men couldn't look at me without laughing for days, John."

Sherlock shoots him a very pointed glare with that and shakes his head to clear his hair away so that John might see it.

"God's sake Sherlock, have you never had a haircut?" John asks skeptically, snickering to himself. When Sherlock makes no mention of ever having received one, he scoffs. "You must've; your hair's not down to your knees."

"Obviously not."

"Well?"

"Well what?"

"How d'you do it then?"

"Do what?"

John sighs and shakes his head; truly, Sherlock is clueless- he hardly recognizes the hair in front of his eyes for what it is; a problem. But then, how is it that Sherlock normally keeps his hair in order? It'd been fine up till now, and John honestly can't picture him ever going down to the local salon for a trim; he'd have all the girls working there in tears before the end of it. There's just no way Sherlock would ever go willingly on his own to let someone have at it without some input of his own.

So, then, what?

"What do you normally do when your hair gets like this, Sherlock?"

"Like-"

"All long and in the way like, yes."

Sherlock pauses to think, frowning when his curly bunch of hair falls back into his eyes. When he thinks about it, though, he finds that he doesn't know. It'd always somehow managed to stay neat and back and out of the way on its own, but now it was wild. How did his hair work? He didn't understand.

He tells John so.

"Well that makes two of us, then." John says with a sigh.

Shrugging, Sherlock turns to resume work on his experiment as John scowls at the conundrum. Eventually though, when no clear solution offers itself to him, he pops open his laptop and gets back to typing up his newest blog entry.

Every once in a while, though, he can hear Sherlock cursing silently at some error he's made, but otherwise things are quiet again between the two. John opens google and begins trying to search for an answer to all this when suddenly the man in the kitchen shouts loudly and rakes his hand across the table, knocking everything he'd been working with to the floor. The tubes shatter as Sherlock storms into the foyer, gripping and madly tugging at his hair.

"What, what is it?" John asks hurriedly, springing up as Sherlock strides by on an angry gait. His eyes scan over Sherlock worriedly to assess him for any chemical burns he may have sustained, but the man refuses to stand still long enough for him to check.

"Mrs. Hudson!" the dark haired man suddenly shouts. "It was Mrs. Hudson! She did it when she knew I wouldn't be paying attention!"

"Oh, is that all?" John says with a relieved sigh, letting his shoulders slump from the tension they'd suddenly gathered. Seeing nothing of bodily concern, he wills himself to calm down and shakes his head. "Christ, I thought you'd burnt your hand off."

Sherlock ignores him as he paces about in circles, grunting madly to himself as the mystery of his well-groomed hair reveals itself to him. He kicks several things about in his tantrum and John rolls his eyes upward and sits back down.

"What's got your knickers in a twist now? She did you a favour, you know; keeping your hair in check for you since you were too ignorant to do it yourself."

"She did it without my knowing!" he exclaims, throwing his hands up as his pace increases. "She led me on to believe that sort of thing was natural!"

"Oh, come off it; surely you'd have noticed-"

"DON'T call me SHIRLEY!" Sherlock says furiously, rounding on John with sudden intensity. "I must have told you three times at least not to do that in the last hour, and yet you persist!"

"Well what about when you were a child, then?" John says irately, ignoring Sherlock's half-cocked threat till the shaggy-haired man begins pacing again. "You didn't have Mrs. Hudson back then, did you."

"Of course not, don't be absurd; it must have been mummy, or someone she hired. God, how could I not have noticed? All this time?!"

"Well you do get in those odd ways when you're really focused." He suggests, a small smile playing at his lips when he thinks about Mrs. Hudson coming in to cut his hair for him when he's in the middle of a stationary experiment.

She'd probably be chatting him up as she did it; talking about whatever celebrity gossip she'd managed to pick up over the month as he waited for some sort of result. He may have even replied and not have even noticed, the bloody idiot.

It was all really rather humorous to John, who couldn't imagine not knowing someone kept his hair magically cut short for him, but found that it was easy to picture in Sherlock's case.

Sherlock was less amused and went to sit across from John in his armchair with a sultry sigh, angrily running his hands through his curls.

"Why'd she stop?" he suddenly asks, looking up to catch John's eye. "If she was so keen on grooming me, then why's she allowed this to become me?"

John shrugs.

"It's beyond me. When's the last time you remember getting a trim?"

'"I don't know," he says sourly, contorting his face into an ugly expression as he thinks. "I don't hardly remember her cutting my hair in the first place."

Sherlock falls into silence as he stares sightlessly at John, trying to remember what may have happened for her to stop coming round annually. Opposite him, John was becoming less concerned with the mystery of the self-trimming hair and was reaching for his laptop again (to add in this new development and add a picture of Sherlock sporting a 'hair-tie' to his older entry) when Sherlock lets out a loud aha! and begins pointing at him accusatorily.

"It was you!" he exclaims, finger shaking. "She quit coming round when you moved in! This is your fault!"

"Oh hardly," John says around a scoff. "I'm not the insufferable idiot who forgot that hair actually grows. Wait till Lestrade and his boys read about this."

Sherlock's lip curls unpleasantly as he fixes John with the ugliest look the doctor has ever seen, forcing him to reconsider blogging about this. Sighing, he shuts his laptop and resigns himself to get at least one thing accomplished if he wasn't to be allowed blogging rights.

"At any rate, the issue still stands that you need a haircut; shall I ring up Mrs. Hudson or call a cab to take you home?"

"Neither." Sherlock says decisively as he, too, comes to stand. Whatever frustration he'd held towards Mrs. Hudson and his mother for conspiring against him seems to have gone from his person as he speaks. "I have good reason to believe that you're handy enough with a pair of scissors; I think its time Mrs. Hudson's replacement, as she apparently saw it, became acquainted with his duties."

And while Sherlock isn't wrong, John's still not 100% sure of what he's supposed to be doing as he stands behind his mate, scissors in hand. He stares uncertainly into the little hand mirror Sherlock's provided for him and takes a deep breathe to steady his nerves.

'Right, well, this can't be too hard, can it?' John thinks to himself as he stares into his unsure reflection.

"Just a little off the top there, old chap," the detective says in a teasing tone. "Don't do anything too young or moody to it; I do have a professional appearance to keep up."

John lets out a snort and takes the scissors up and begins to cut.

It occurs to him after the first few snips that he has no idea what he's doing. He thought at first that the important thing was to make it so Sherlock could see again, but amidst all the twists and turns his hair makes, John can't tell if he's making even cuts or not.

Of course, he's had experience in trimming down his own hair from time to time; kept it neat and short and close to his scalp in times when a salon wasn't accessible, but he was beginning to see that when it came to curly hair, just cutting straight across wasn't going to do the trick. He frowns and decides to grant access to Sherlock's eyes last to save him the embarrassment of having to witness the coming of what was sure to be a Terrible Haircut.

They don't talk as John works. Sherlock fidgets in his seat impatiently from time to time, (always causing John to make a wrong cut he then struggles to fix, but only ends up making worse) but was overall content to let his companion focus on making him look presentable.

After a while, John figures he's done all he can do and puts the scissors down. The result is not good.

"Erm. So that's that, then."

None of the sides are even; its too short on one and grossly misshapen on the other with various, thick strands that have suddenly decided gravity no longer applies to them stick up oddly throughout. John can't meet the ugly glare Sherlock is giving him as he inspects the doctor's handiwork with the little mirror.

"John." He finally says as he places the mirror calmly on the table. When John doesn't answer, he turns in his seat and presents him with a thin-lipped frown. "John, surely you can see that this is an unsatisfactory cut. I demand a do-over."

"Well, ah, Sherlock, you do know hair doesn't grow back on command," John says and clears his throat to hide his laugh. Oh God, does Sherlock look terrible. "Or maybe you don't; anyway, don't call me Shirley."

John knows he should feel bad about this; knows he should be embarrassed at the quality of the cut he gave him, but when Sherlock looks at him like that with his hair so irreparably tortured, he just can't find it in him to feel anything other than incredibly amused.

He ends up laughing so loudly that Mrs. Hudson eventually has to come up to chide him for making so much noise. She starts to speak when she catches sight of Sherlock and lets out a horrified gasp, making John laugh all the harder as Sherlock mopes away to try and seek out his flap-eared hat.

As ugly as it is, he knows anything, absolutely anything, would look better on his head than John's terrible handiwork and does not stop sulking until his hair grows back out.