On the flip side, self-control, impulse control, being able to manage your emotions with a toolbox: these are skills that are learned, honed, and mastered. Sure, many people learn them through other means than from their parents, often as a survival necessity in their environments, but I don't think that e.g. the people who fly off the handle and get into a bar fight when someone's hitting on their girlfriend, are doing so because of heavy metal poisoning or genetics.
That's far from obvious. You can't just observe some trait in an organism, and conclude "that must have genetic origins".
I got news for ya bub. They aren't learned. They can be honed to a small degree. They cannot be mastered.
When you have ADHD you realize this.
And to your last thing. Not in all cases but in some.
(I'm not arguing for or against the point that they can be learned, just against the "proof" that someone with ADHD has - and not because of ADHD specifically, but because generally speaking any argument which relies on "my experience proves X about humans" is likely to be short-sighted.)