I've made a few corrections and changes to this story.
The storm had picked up in strength within the last couple of hours and the rain was coming down sideways. John would have taken a cab, if it wasn't because Sherlock had snatched the last 20 quid out of his wallet and he hadn't noticed until he was about to go home from work. Not that it would even be possible to get a cab on a day like this, but John needed someone to blame for having to walk home in this weather. He was soaked to the bones, when he finally arrived and his toes and fingers could just as well be freezing off for all John knew. He slammed the door shut behind him with his teeth clenched, partly because he was angry and partly to keep his teeth from chattering. Up the stairs, and through the door, slamming this one as well, though not quite as hard. Sherlock was laying on the sofa, thinking, obviously he had not been outside that day, but at least he was dressed.
"You're upset," he stated, but he didn't open his eyes.
"Damn right, I am," John agreed and threw his jacket on a hook. He didn't even bother to sit down to get his shoes off.
"And you blame me," Sherlock continued as if they were having a conversation about the weather. Well, the weather any other day.
"You took my last 20 quid, I had to walk home!" John yelled.
"Yes, I did, John, but that's not it." Sherlock still didn't move. John stared at him with a dull look for a moment. He didn't have the energy for this today and threw off his soaked jumper. It landed on the floor with a heavy thump, and John picked it up again to hang it over the back of a kitchen chair. He shouldn't take it out on Sherlock. Instead, he went to his room to put on dry clothes.
"I'm sorry, Sherlock," John muttered with a scowl when he stepped into the living room a while later.
"Of course," Sherlock replied. He still hadn't moved, but now he jumped up and eyed John. "You are still freezing."
"Yes," John breathed with his shoulders slouched forward. Sherlock raised an eyebrow at his shorter friend, but kept his lips tight together. John looked up at Sherlock, who were facing away from him, and John just sighed. He sat down on the sofa, exhausted. Sherlock flopped down next to him. They sat in silence.
"I've been thinking, John," Sherlock said. John leaned back and made a 'hmm' as response.
"John."
"What have you been thinking about, Sherlock?" John said a little too enthusiastically and sat straight up to direct all his attention to Sherlock. Sherlock smiled and cocked his head. That smile warmed John inside out and he leaned back with his arms crossed.
"You see, John, what I've been thinking of," Sherlock said, but stopped abruptly. He strode across the room to pick up a blanket and throw it at John. He then proceeded to pick up the sentence as if no break had been there at all:
"is, that while you are far much more special than you think." John blinked and his expression softened. Sherlock stood in front of him and looked down.
"Which, of course, is not new knowledge, to me at least it isn't, but it has occurred to me, that you may not be entirely aware of it," Sherlock ended his sentence and looked long at John, who made no movements.
"Excuse me?"
"I said," Sherlock sighed and sat down again. "That you are special. I think you should know that."
"Oh," was all John could master. He frowned and looked down.
"Really?"
"Yes, John. Why else would you be my friend?" Sherlock smiled a warm smile at John. He put his hand briefly on John's thigh before getting up and walking towards the kitchen.
"Tea?"
This story has a sort of sequel called Sick, in case you're curious for more.