Just a quick, humorous story :) All rights to BBC etc...
Sherlock jumped slightly, startled. It took him a second to notice John standing by the couch, a curious expression on his face. Lock sat up, annoyed. "What?"
"I made you tea… What are you doing?" his friend asked suspiciously.
"I'm thinking!" Sherlock snapped. "Was thinking."
His guilt trips never worked on John. "You were talking to yourself… Something about pirates?"
The detective winced and sat up. "Pirate Bay," he said, improvising quickly. "Online. I'm going to download Henry Knight's documentary."
"Mm," John said, unconvinced. He sat down in one of the nearby chairs. "And these online pirates – they look for buried treasure, do they? And say 'Arr'?"
Sherlock closed his eyes. "Yes, all right," he said, frustrated. "I was thinking about pirates."
John grinned. "Mycroft did say you had chosen that career before you became a detective," he said, obviously struggling to hold back giggles.
Lock looked up at him sharply. "You talked to him about me?"
"Don't change the subject, Captain Holmes," John said, finally failing to swallow his laughter.
Sherlock pulled a face and stood up to go into the kitchen. "And I suppose you never fantasize?" he sneered.
"Of course I have fantasies," John said. "Tea's on the table, biscuits in the cupboard," he added before Sherlock could ask. For the "greatest detective in the world," he really was blind sometimes.
"Not that kind, John," Sherlock said, carrying the tea and snack back to his couch. "Didn't you play when you were a child?"
"Yeah, but that was years—"
"What did you daydream about?" he interrupted. His pierced blue eyes locked onto the doctor, questioning, curious, and as always, nonjudgmental.
"I… it's been too long," John answered, speaking into his tea. "I don't remember." He took a drink and tried not to look conspicuous.
It didn't work.
"Of course you remember," Sherlock said, dunking a biscuit into his tea. "We don't forget our safe havens; that's what dreams are."
John sighed; he couldn't keep dignified while Lock was being so sincere and innocent. "Fine," he said. "I wanted to be… Peter Pan." At Sherlock's frown, he continued, talking to his tea again in embarrassment. "I read the story when I was a kid. To never grow up, you know…"
Sherlock grinned. "I knew it," he said.
"No, you didn't."
"You're right; I never would have guessed." He was silent for a moment and then started to laugh.
"What?" John asked.
"Peter Pan and a pirate," Sherlock explained, still laughing. "No wonder we fight so often."
John chuckled. After a moment, "Does that make Mycroft the crocodile?"
"And Anderson's a codfish?"
Both the boys had to set aside their tea for fear of choking on it in hysterics.