A/N I've always wondered what it was like when Sherlock first told John about his mind palace.

Thanks to MapleleafCameo, johnsarmylady

Disclaimer I don't own Sherlock or any associated characters, events, etc.

LII. Deep in Thought

"Wait, a palace?" John repeats, clearly trying to hold back laughter.

"Yes." Sherlock narrows his eyes, irritated. "A palace. It's… the visualization that works out best for me, and before you begin to criticize that, I'd like to kindly remind you that someone with your mental capacity probably couldn't manage to envision so much as a mind closet."

"Alright—alright, I'm not insulting you." John holds his hands up, but hurt is vivid in his hazel-blue eyes. It's obvious that he doesn't like being called unintelligent, but he puts up with it, never tells Sherlock outright to just stop. The detective probably would lessen the flow of insults directed at John's cleverness if only the doctor did ask him to stop, but apparently his pride level is too high for such a request.

"It's actually a rather common memory technique, and a highly effective one, though it takes a tremendous amount of focus—hence my inability to respond to you when I'm immersed in it."

"So, it's like a sort of trance?" John questions, leaning forward on his elbows.

"If you want to use such a vulgar, primitive term," Sherlock mutters. "In any case, you're distracting—that's why I tend to enter it only when you're out of the room."

"I… distract you?" he repeats. His eyebrows draw together in clear confusion. "How am I distracting? I can be quiet, if you want, just sit in the corner or whatever… I don't mean to interrupt you—"

"That's beside the point," Sherlock snarls, trying to deal with his own frustration. The truth is that he's unused to such interference; usually people in the room isn't the sort of thing that bothers him, so long as they're minding their own business and not making too much noise. But with John… John's different. It's as though, when the other man is in the room, Sherlock's attention needs to be at least partially focused on him. He can ignore him sufficiently enough to experiment and such, but for something as absolutely concentrated as his mind palace… he can't do it, with John there. It's impossible. "Just… try to keep out from now on. I'll let you know when I need to consult with myself."

"Consult with yourself," John repeats, shaking his head in slight, entertained disbelief before nodding and sitting back. "Alright, I can do that. So long as your little ventures aren't so stupidly frequent."

"I can try to keep them as sparse as possible," Sherlock agrees grouchily. "But sometimes such a thing is essential, and you're going to have to learn to deal with it."

"I'm trying to be agreeable, Sherlock; you don't need to get all snappy on me. Okay? I think this'll work out just fine for both of us. I'm sorry for being such a… distraction."

"It's fine," Sherlock grumbles, crossing his arms. He's not angry at John—well, not John himself in any case. He's just confused. Since when does a single person keeping to himself serve as a distraction?