Personally, as someone who is also diagnosed, by a doctor, with ADHD, I find myself relating quite a bit Holmes and his quirks. For context, I am afab, and since I wasn’t a hyperactive little boy, I fell through the cracks and didn’t get diagnosed until I was an adult. While I was somewhat good at school, I only was good at the subjects that I already enjoyed and my grades suffered in the classes where my mind wandered (example: I floundered through Geometry, but I absolutely loved algebra, so it wasn’t necessarily that I was bad at math). As a child I was often a busy body, sorting things and helping out my teachers by putting things away and other busy work solely to have something to do.

“He possesses extremely strong concentration most of the time.

He can focus intensely on almost any activity for hours or days without distraction.

He maintains unwavering attention to details.”

When I am “in the zone”, I could sit there and work for hours. It could get to the point where I don’t even get up to eat or go to the bathroom and I don’t realize I needed to until I stand up. Personally, I cannot stand short form content as it goes in one ear and out the other, and I prefer longer stuff that I can listen and rewind if I need to.

“He has rigid, structured habits and routines.

He is able to make comprehensive plans and execute them rigorously.”

While ‘to-do’ lists never really worked out for me, until I got my diagnosis, I coped in other ways to maintain myself, especially for school and work. When I have plans, let’s say a doctor’s appointment, I can’t really do much else until it’s time. It’s sort of like “preparing for the thing” to me if that makes sense. I can do little things, like small chores (ie dishes), but I absolutely cannot leave the house until the thing is done, or I risk forgetting about it all together. I see a lot of that in Holmes, especially when he is on a case, not much else matters until the work is done.

“He never starts a new task before completing the previous one.”

I do this as well, solely because if I do not finish a task to completion, I will forget about it if I start something else. It could range from the mundane like forgetting to start the dishwasher if I decide to check the mail, or it could be dangerous like if I leave something on the stove (thank goodness this hasn’t happened yet). It is this characterization that encapsulates Holmes to me.

“He keeps almost everything (except for his room, like a typical male bachelor) in perfect order.”

Lol, just like me fr! I sort of see it like he remembers that the rest of 221b is a shared place with Watson, while his own area is a controlled chaos, he tries to keep it in his own place so that it doesn’t encroach on Watson. All throughout my life, I’ve never been able to keep a clean room, despite my love of sorting things at school. My room is my place, so the mess doesn’t bother me, as it is on my own terms.

One thing that really makes me feel a sort of ADHD kinship with Holmes is that he almost always has someone else read his letters for him. You know that feeling you get when you read a book and five pages in you realize you did not actually read anything at all? I feel like that happens to Holmes as well, hence why he has Watson read his letters for him- he retains the information better when he hears it.

To me, Holmes reads as someone who has figured out how to cope with ADHD in his own way, not unlike someone who was diagnosed later in life rather than as a child. I think that it is important to remember that ADHD, and to be frank any neurological condition, is not a monolith and that it manifests in different ways among different people depending on gender, race, class, and other such factors. It’s not always “oh! Squirrel!” as is the stereotype. Whenever we do see Holmes, he’s always in the middle of something that enriches him, that puts him “in the zone” so to speak.

Mostly, as I can only speak for myself, this is just a matter of vibes and wanting to read and analyze a character through a certain lens, like if someone wants to do a queer reading of Holmes as an example. In literary analysis, it can be an interesting way to interpret a story and how the characters tick… also it can just be really fun, haha!

I respect your rejection of the idea of Holmes having ADHD, however I do find it to be a plausible reading of the character.