[And said dealer would probably be getting a visit from a certain department of the government sometime soon, and so would the local police, and the school if he had something to say about it...Mycroft was working on plans upon plans in his head. It would not be pretty if he found the actual dealer Sherlock used, too.]

It's not entirely meaningless--yes, people are idiots and it's dreadfully tedious, but interpersonal relationships can be manipulated--

[He drops off. Sherlock wasn't like him, he didn't find the same sorts of things that interested him stimulating.]

Of course, naturally. What led you to seek them out, for the first time?

[He needed to find his triggers.]