I'm not even talking about 'not being able to concentrate' because that's easily fixed with medicine. nowadays But ADHD is so much more involved on the emotional and psychological level.
My childhood was mostly 'driven by impulsivity', so having medicine available to me back then doesn't sound bad.
That's the definition of being a child.
Do you think that a child is driven by long term planning or wisdom?
But for example, I picked my next school based on where my elementary school friends went and insisted to my parents that this is where I wanted to be, despite it being a worse choice for my then-grades. And then a few years later again, I picked for my school path to be economics over math (what I actually wanted to do), because my friends picked it.
Or, I was convinced for a while I wanted to work in a hotel post-school for no reason, despite learning programming by myself and being a computer kid writing my own programs and websites. I even applied to hotel-related jobs constantly until my parents pushed me to go to software engineering instead.
So what I mean with 'driven by impulsivity' is that often important decisions aren't handled with reason, but with pure emotion and impulses. Most of the time that's fine when you're young, but there are still times when you want to use logic over impulses.
When the mood strikes me, I make GRAND long term plans. Then, when I'm gripped by impulsively, I try and keep it honed into the plans I made.