Sherlock reached his conclusion quickly. Dorm rooms are boring.
Lying outstretched on his bed, fingers steepled above his chest, Sherlock was waiting not-so-patiently for John to return from rugby practice. Why he had to choose to play rugby was beyond Sherlock. It was a pointless game; too few tactics and more to do with how many aliments and injuries you could get from being slammed to the floor by the most idiotic boys in the school. Boring. But the most annoying thing about it was that for three days a week he'd have to live 2 hours without anyone to talk.
The waiting was agonizing if he had nothing better to do. Sometimes of course he spend it in the Chemistry lab or reading. But the rest of the time he couldn't help but remember the small packet of white powder that he'd stashed behind their chest of drawers. He'd only ever done a few times before firmly telling himself that cocaine damaged the neurons irreversibly, which of course could lead to a possible drop in brain function and IQ. Of course he'd kept his find and intended to sell it on- there was no point wasting good drugs- but the temptation was still there.
He looked at the time. 5:22. John would be back soon but he'd probably be able to get it out, have a line and return back to normal before his friend got back. Not that he'd suspect anything anyway, John went through life in a kind of unobservant dream.
((this is a little young Sherlock thing with His-Doctor but anyone is welcome to join oh and I hope you like the title I had no idea what to call it))