I think my problem is just the opposite. When I write him, as a guest character in my OUAT fanfiction work, I make him a little too mature and serious. Then again, he did take on a powerful spell that robbed him of his ability to love, or to regard anything other than as a means to information or to mock for their stupidity, regardless of their emotions.
I haven't seen it, though that does sort of sound like something Sherlock would do. I can imagine a teenage Sherlock, at one of the Christmas dinners that his parents holds, coming down in only a sheet because he didn't have clean clothes. "Well, would you prefer it if I was naked?"