Let's talk Diogenes Club.
Started so a bunch of guys could read newspapers and magazines in comfy chairs . . . sooooooo . . . a library? (They have comfy chairs these days, at least in Peoria.) No talking is allowed upon pain of expulsion, three strikes and you are literally out, like it was designed by the strictest of stereotypical shushy librarians.
Mycroft Holmes was one of the club's founders. Now, we all assume Mycroft was a bachelor who lived alone, which would mean his place was probably pretty quiet and he could do all the reading he wanted. Soooooo . . . he did it to save money on periodicals? But as I said, he was one of the club's founders. He had to put enough money into the thing that he surely could have bought his own magazines. And even his business-startup baby brother could afford all the newspapers he could read.
Are we making too large an assumption in thinking Mycroft had no one in his lodgings that he was trying to escape on a regular basis? If not a family, a really annoying counterpart to his brother's Watson? We have a definite bias toward characters in books we read to not give them any more family and friends than we are handed in the pages we read.
The Diogenes Club was definitely an escape plan from something.
We sometimes consider the Diogenes Club a place for people who didn't like people -- but why would someone leave a perfectly good private apartment to go somewhere and sit among other people, even if they aren't talking? I've seen cats that don't particularly like each other sit a few feet apart and ignore each other, but those are cats and who knows what they're thinking? Members of the Diogenes Club wanted to be among like souls, to see and be seen, yet not interact. Were their social skills that horrific that they needed the no-talking rules just to pretend they had social lives?
Or was this a club for souls who desperately needed some control in their lives, to go somewhere where no random interactions could happen. A prison, of sorts, that didn't lock you up, but locked the world around you up. There have been many a theory that the Diogenes Club was tied to the early intelligence community of Great Britain. (Why do we never hear of the other Not-So-Great Britain?)
One can theorize all sort of things about the Diogenes Club and what it reveals about Mycroft Holmes, but theories are all we really have. It sure looks good on paper, but beyond that? So many questions.