MYCROFT: And Sherlock played among the funny gravestones.
JOHN: Funny how?
MYCROFT: They weren’t real. The dates were all wrong, an architectural joke which fascinated Sherlock.
—The Final Problem, Sherlock S4
There were, however, certain obstacles in the way, and the true history of this curious case remained entombed in the tin box which contains so many records of my friend’s adventures. Now we have at last obtained permission to ventilate the facts which formed one of the very last cases handled by Holmes before his retirement from practice. Even now a certain reticence and discretion have to be observed in laying the matter before the public.
—The Adventure of the Creeping Man
When one considers that Mr. Sherlock Holmes was in active practice for twenty-three years, and that during seventeen of these I was allowed to cooperate with him and to keep notes of his doings, it will be clear that I have a mass of material at my command. […] Concerning these latter, I may say that the writers of agonized letters, who beg that the honour of their families or the reputation of famous forebears may not be touched, have nothing to fear. The discretion and high sense of professional honour which have always distinguished my friend are still at work in the choice of these memoirs, and no confidence will be abused.
—The Adventure of the Veiled Lodger
I have never known my friend to be in better form, both mental and physical, than in the year ‘95. His increasing fame had brought with it an immense practice, and I should be guilty of an indiscretion if I were even to hint at the identity of some of the illustrious clients who crossed our humble threshold in Baker Street.
—The Adventure of Black Peter
It is years since the incidents of which I speak took place, and yet it is with diffidence that I allude to them. For a long time, even with the utmost discretion and reticence, it would have been impossible to make the facts public; but now the principal person concerned is beyond the reach of human law, and with due suppression the story may be told in such fashion as to injure no one. It records an absolutely unique experience in the career both of Mr. Sherlock Holmes and of myself. The reader will excuse me if I conceal the date or any other fact by which he might trace the actual occurrence.
—The Adventure of Charles Augustus Milverton
The architect (someone who creates the structure of something) played a ‘joke’—he messed about with the names and dates. Just like John Watson (the narrator), just like ACD (the writer), just like the Sherlockian fandom itself. It is worth noting that the episode circles around Sherrinford, a concept/person which grew out of ACD messing around with a name, and which became a fanon creation with a life of its own.
The ‘architect’ also includes Mark/roft—who tells this story, constructs and filters this part of the episode, even to the extent of transporting sections of memory back and forth in time using the cinematography—normally something only Sherlock’s mind palace can achieve.
Green Violin Bow 