That's not ADHD man.
Unless you mean energy, intensity, drive and singular focus for something and the next day you forgot all about it and it's onto the next shiny thing.
For example, 3 hours ago I decided I want to write a video game. Never written anything more complex than PONG in my entire life. I know myself enough that I'll be writing down all the fancy ideas I have, and we'll see if I still want to do it in 2 days.
I’ve done the video game one before. Not coincidentally, it had an aquatic theme. I lasted like 2 weeks. I wasn’t discouraged by a lack of interest necessarily, but the sense that it was truly impossible to pursue.
I know some other people with ADHD who have very central and long-lasting interests, but you’re not wrong that the passing (and often even more intense) ones are real too. Perhaps more common as well.
That’s why I said “some presentations”; some people find a groove that allows them to go deep on something they’re interested in, I guess. But certainly not always.
If it weren't for the need to occasionally comply for work etc, "ADHD" would be pretty neat and fun. Being mercurial and intense can be isolating, though.
I get interested, I seek out the most direct and as far as I'm able to gauge, best information related to the task I'd like to complete and I consume as much as I can about it until it's done or I'm bored. Or something else takes the intensity. I can juggle 2-3 intense interests at a time, this helps keep them going longer as I'll shift from one to the other if I hit a wall.
My kids are often confused why I’m interested in things (most recently fish and frogs I found in a creek, or enormous boulders we came across on a forest floor which likely fell there from incredibly high rocky peaks hundreds or thousands of years prior) but to me it’s like, how can this not be exciting!? In both instances I was so deeply engaged and amazed by the subjects and it gives me this incredible sense of awe and appreciation for the world I live in. The rest of my family is so uninterested that my interest annoys them, haha.
There’s definitely a downside of course. Like you mention, losing interest in things usually means moving on to something else, but that’s not always a good idea or beneficial to myself or those around me. Even so, I love being able to get into things so intensely.
Yes that is how exactly ADHD works. Focus is there, but not in our control.
The psychiatry stuff starts at around 8 mins in.
I don't think Tom Cruise is fully unreasonable and certainly don't think psychiatry is a reasonable arbiter either.