John learned very early in his friendship with Sherlock that it was worth his while to ensure that his roommate never became bored. A bored Sherlock was a dangerous Sherlock (he was also an unpleasant Sherlock, but since Sherlock could rarely be described as pleasant in any normal sense of the word, that bothered John less). A bored Sherlock shot holes in the walls, filled the refrigerator bins with thumbs, and poisoned himself in the extremely dubious name of science.
But that, John feared, was nothing compared to what a Sherlock on crutches and confined to 221B Baker's Street might get up to.
Try as he might, not even Sherlock could argue his way out of a torn ACL (torn while chasing a suspect across a rooftop, of course) and subsequent surgery, nor could he reluctantly call in a favor from Mycroft to make it vanish. Since those were Sherlock's main coping mechanisms - if they could even be called such - he was stuck in the flat. The only person more unhappy about this situation than Sherlock was John. He seriously considered going to stay with Harry for a week or two, but neither his medical training nor his moral compass would allow it.
That, of course, was in the broad light of day. At four in the morning with Sherlock's violin shrieking in the sitting room, John had quite a different opinion on the matter.
"For fuck's sake, Sherlock!" John shouted, storming down the stairs. "Are you murdering a cat?"
Sherlock, ensconced in his nest on the sofa, glared. "If you don't like it, you're welcome to leave."
"I certainly am not welcome to leave," John said, yanking the violin out of Sherlock's hands and putting it very deliberately on the other side of the room. "But I am entitled to a decent night's sleep before another day of fetching and carrying for you. Now what's the matter? Can't you sleep?" The Remedeine had the welcome side effects of putting Sherlock out like a light for at least an hour or two and making him rather mellower than normal the rest of the time. John had been vigilant about forcing him to take it every four hours as prescribed for this very reason. Though he supposed he should have set the alarm for three o'clock; Sherlock had now missed a dose, and this appeared to be the direct result.
"No, I can't sleep," Sherlock snapped, scowling. "My knee hurts, my head aches, and I despise this brace." He glared down at the buckles, straps, and Velcro encasing his knee and, indeed, most of his leg. "What good is a body if it doesn't do as it should? It's meant to be transport, John! If it can't be that, then what the hell good is it to me!"
John sighed. He found the painkillers (which were well within Sherlock's reach) and freshened up his water bottle from the kitchen tap. "Here," he said, holding them out. "Take them." Sullenly, Sherlock did so. "Now, you listen to me," John said, pulling a chair up close to the sofa. "I realize you'd rather be a brain in a jar, but you're not. You pushed your body to its limits, and now you have to deal with the consequences. It's going to be uncomfortable and tedious and you're going to hate it, but you must learn some patience or it'll be far more miserable than it needs to be."
Sherlock shook his head and looked away. "Patience is hardly my strong suit, John."
"It can be," John said. "I've seen you be very patient when it had to do with a case." Sherlock didn't answer, nor did he look at John. John counted to ten inside his head. "Look,” he said at last, “it won't be all bad. You hardly leave the flat most days, anyway. Lestrade and I can figure out a way for you to continue to consult." At least he damn well hoped they could. It was either that or drug Sherlock into a stupor for the duration of his recovery (appealing thought, that, but impractical).
Sherlock appeared ever so slightly mollified. "Do you truly think so?"
"Why not?" John said with a shrug, praying Lestrade would agree. Privately, he suspected the DI was rather looking forward to several months free of his consulting detective, but it wasn't as though Sherlock weren't useful.
"Well," Sherlock said, "I suppose that would make this situation slightly more tolerable."
"Good," John said, and reached out to pat Sherlock's shoulder as he stood. "I'll do what I can, I promise. But I swear to God, Sherlock, if you wake me up again with that sodding violin, I will throw it out the window and into the street."
Sherlock stared at him in horror. "It's a Stradivarius! You wouldn't!"
John put his hands on his hips. "Do you really want to test me?"
Sherlock shook his head. Satisfied, John helped him settle himself against his pillows and reposition his knee. By the time they were done, Sherlock was already a little glassy-eyed from the medication, and John didn't think he'd have any trouble getting back to sleep.
Still, John took the violin up to his room with him. There was no use taking any chances.