Sherlock did not require the amount of sleep that the average adult needed.
In fact, he could go for extremely long periods of time without sleep, although this usually ended with him passing out for a good 24 hours as his sleep debt caught up with him.
In an ideal world he wouldn't have to listen to any of his bodies demands, but seeing as that was highly improbable, he would have to acknowledge his bodies weaknesses from time to time.
But that didn't mean he had to like it.
He was also well aware that other people were not as efficient as himself.
Mainly because they would not stop nagging.
There's no milk Sherlock. Why is there never any milk in the fridge! I bought some a few days ago, there should be milk. Why do you expect me to go and get milk for you all the time...
Why did you wake me up! I'm tired, I haven't slept properly in three days. No I don't want to go with you to look at blood spatter patterns of the victim to prove a point to Lestrade, it's 3 in the morning. No I won't send a text instead it's 3 IN THE MORNING...
I'm hungry. I can't even remember the last time I ate. I don't care if you don't eat anything I very well am going to. And if you then you had better tell me before I get home with the food because I don't want to have to starve because you changed your mind at the last moment and expected me to hand over some of MY food...
Nag nag nag nag nag.
But the most annoying of those rants John takes upon himself to inflict the world with, he muses, are the ones concerning directed at him.
Sherlock when was the last time you ate?
Sherlock when was the last time you slept?
Sherlock when was the last time you had a shower?
Sherlock when was the last time you shaved?
It's days like these he feels like strangling his flatmate to death.
Painfully and slowly.
He can go for a very long time without eating and supplements tea and nicotine anyway, so food has never been much of an issue.
Very rarely is he anything less than immaculate and on those occasions, he admits, a shower would be called for.
He always shaves. It was just that one time for a case that John only brings up to tease him about...
But sleep?
While he can go for a long time without sleep, it always catches up with him. There is no loophole like there is with consumption, he'll simply wake up and find himself on the floor after passing out from exhaustion, enraged by the slowness of his mind during the waking stages and thoroughly irritated by his 'weaknesses'.
But sometimes he'll wake up on the couch with a warm, thick blanket on him and his head comfortably propped up on a pillow.
And then, he won't mind quite so much.