Like yourself, until diagnosed, I would have never considered ADHD a possibility because I would regularly focus intently on a programming project or random wikipedia rabbit hole for hours and hours at a time, often skipping meals and staying up until the early hours of the morning. But it turns out these trances of hyperfocus are typical for many ADHD sufferers. There are different flavors of ADHD. I never experienced the hyperactivity that often leads to diagnosis in children.
Keep in mind that one of the requirements for diagnosis in the DSM is impairment in social, academic or occupational function. In my case, spurts of hyperfocus routinely kept me from maintaining healthy sleep, diet, and hygiene routines, and ADHD also prevented me from doing homework and chores that were uninteresting. Unfortunately, there are precious few people who are able to exclusively focus on whatever engages their fancy at the moment. For me, it was debilitating.
Check out the video brazzledazzle posted above. You'll learn ADHD is way more nuanced than the popular understanding.
Frankly, the description you have given is very similar to AD/HD, especially the "I'm that fucking good" part. Yes, I know you weren't bragging, but that sense of infallibility and the letdown that invariably follows when your abilities don't manifest ... I'm guessing it sours you to the project you're working on? Can't seem to direct yourself back to it to care again like you did when you were focused on it the first time? Anxious to find something else that's more interesting where you can prove what a rockstar you are? That rush when you pull that rabbit out of the hat, feels good, doesn't it? Dopamine is great, when you do something that creates enough of it that your brain feels rewarded. For many, it doesn't take much. For many people with AD/HD, the last minute YOLO cramming/programming/building/working session is what it takes to feel like we're doing anything worthwhile.
EDIT: I guess that means either you don't have AD/HD, or just something else that inflates your sense of your abilities. Maybe you're just addicted to the rush of the looming deadline? I don't know. I'm not a psychiatrist.
- Lack of awareness or concern for timelines until immediate consequences loom.
- Inability to control focus if not emotionally invested. (So-called hyperfocus is much part of ADHD as is non-focus).
These are both things that would light up an ADHD scoreboard. They're almost direct quotes from the literature, and if you spoke to a group of ADHD people they would recognize them immediately.
People with ADHD have many explanations for "why" they are this way. A lifetime of rationalization does not make it not so. So perhaps talk to an ADHD specialist - it can make a huge difference in your life, and your loved ones.
Ask someone diagnosed in later life, say, over 40, if they would have preferred to not be rationalizing and suffering the consequences over the last 20 to 30 years.
But when it's stuff I don't enjoy or I'm a bit down, it's a totally different ball game.
I also tend to not be concerned about dates far in the future because I secretly believe I can pull a rabbit out of the hat whenever I want and get the 1 month task done in a day, I'm that fucking good. Of course, I'm not.
ADHD is not something to be flippantly tossed around on not being able to do stuff until a deadline, that's just classic procrastination. I know you didn't mean to sound flippant, but you are being flippant and also I don't think it's a good idea to start conflating ADHD with procrastination.