This is the first time I've read a description of ADHD, even if it's plastered everywhere on the Web, so consider my reaction genuine and not intended to offend: isn't this just a mix of lack of willpower (potentially subconscious, which could explain the "forgetting" part) and ennui/depression?
In french, we have the word "flemme" that can be approximately translated into "laziness", but it's a bit different, because "flemme" is often construed as an enemy within, something you have to fight, and some people have more than others.
I think it's slightly different than that, in my experience as someone with both ADHD and occasional struggles with depression. For depression, there is this distinct sense of ennui, or that things aren't worth bothering with, that feels present enough emotionally to "identify" with as part of your intent.
But when that's not there, the ADHD ends up manifesting as this sort of detachment of my own thoughts and feelings from my actions. I may be doing something, and there will be in many cases an internal train of thought that's recognizing that there's something else important I should be doing (say, stop engaging with a hobby and go to sleep), and understanding and being alarmed of the consequences of not doing so, but even with that conscience desperately pleading to act on it, for whatever reason, there's a disconnect that makes it not persuasive enough to take action on. And so I stay up late, not wanting that and fully knowing it's a bad idea.
That tends to lead to a lot of mental anguish, and it did unfortunately eventually develop into a sense of futility for me. Because "learning from your mistakes" ends up being ineffective, since you can't use that knowledge to reliably persuade yourself anyway. Before that I instead was just constantly confused and disappointed in myself for not being strong enough to resist it like I was always told I should be able to, if I really believed in it. I'm honestly still not sure which of the two is a better mentality to have, I'd say they both felt catastrophic or occasionally helpful for me at different times in life.
In french, we have the word "flemme" that can be approximately translated into "laziness", but it's a bit different, because "flemme" is often construed as an enemy within, something you have to fight, and some people have more than others.