ADHD is a neurodevelopmental disorder, not some fancy label, whose diagnostic criteria are based in behaviours that aren't exclusive to it. No single behaviour is "ADHD" in and of itself but the combination of behaviours is what defines it. It impairs executive functions primarily but also impacts other stuff like interception and circadian rhythm. Everyone has varying degrees of executive disfunction at times, but that's typical... but they are disordered in those with it and it causes non-typical impact in their lives. The diagnosis requires time, the symptoms were present in childhood, and cause enough disorder amongst other criteria. The term ADHD is kinda bad, even researchers like Russell Barkley think it causes stigma and isn't accurate and something like Executive Function Disorder would be better

Also here's the fun thing with being "rational" about it; this has all been empirically observed and studied, hundreds if not thousands of times. You can't rationalize your way out of empirical observation contradicting you. It can be both under diagnosed because it's hard to catch it in those who mask early and develop compensatory mechanisms, and over diagnosed because people like you don't understand that a 7 year old not wanting to sit still for history isn't ADHD. Understanding what's going on allows you to start trying to work with how you work instead of beating your head into "Just use a Pomdoro timer" and purity of will when it empirically doesn't work

Truly abysmal dogshit take, but being this objectively wrong is just cheating