Love this! I hope you will consider submitting this to thankyoubbcsherlock on Tumblr - On Friday, September 5, 2014, flowers and the blog URL will be sent to the show as a gift of appreciation for all the pleasure "Sherlock" has brought so many of us. Submissions will also, as I understand it, continue to be added to the blog after that.
Dealing with High-functioning Sociopaths for dummies I think he'd be more likely to be reading something about Asperger's, maybe that's where he got the idea. I adore the idea of John caring enough about Sherlock that he's willing to learn more about his "condition" so that he can understand and communicate with him better. John's probably reading something like, "they have trouble recognizing social cues" and thinking, well he obviously doesn't understand the concept of personal space."