It had been hours from when John had gone to work and Sherlock couldn't even feign interest in the various experiments he was conducting with tupperware and a food processor. He knew he was being watched and it made his skin prickle. It would be glamorous and exciting if it were Moriarty. Little specks of red lighting up on his chest. Perhaps even a foreign enemy, cameras hidden in the sugar bowl.
But instead it was his elder brother; and that bored him. He had been evaluating a great many things lately, not the least of which being his brother. It occurred to him one chilly morning as he stirred his tea- what would he do if Mycroft died? Would he care of his aging parents? Could he survive knowing that no one would truly know him and the things that made him this way? Life, he was sure, would be so very difficult if Mycroft weren't clearing obstacles Sherlock could barely even guess about let alone know about.
This arose amidst many morbid thoughts. He pondered what John had once said about normal people. They have friends, family, people they like and don't like. Normal people with normal lives.
Sherlock had an unimaginably chaotic life and still he was bored. He only began to feel content when he had, well, friends. His greatest concern was no longer 'The Work'. It was no longer 'The Drugs' and no longer 'The Game'. It was John. It was Mrs Hudson. It was Molly.
His many sugars had long since dissolved when he came to the conclusion that perhaps identifying tobacco ash had been, largely, a waste of time. Perhaps caring could be an advantage, perhaps he needed sentiment.
It was now when he heard the door below open and close that he glanced at the clock. It had been hours, he had been daydreaming, thinking. John was home.
"Sherlock, you could probably tell your brother that the camera in the door knocker should at least try to be inconspicuous," John called as he hung his coat up.
Sherlock was roused from his thoughts and decided he and John would need another case. Something to analyse. Something to stop him from analysing himself.