ADHD isn’t a disorder in the sense that people that have it are “ill”. It’s a personality type, and the disorder part of it comes when the characteristics of that personality conflict with then life you lead.
So of course children with ADHD do not function well in classroom settings where they’re supposed to just sit still and focus on something they’re not very interested in, all day. Most kids have some trouble with that. Kids with ADHD personalities really struggle.
The same is true of adults. Some adults with ADHD gravitate toward professions that suit their personalities and thrive. Others have a lot of trouble trying to succeed in their work. A common pattern in high-achieving ADHD people is to do really well in school up until university, and then crash and burn once things get actually challenging.
There are also a lot of interpersonal issues that people with undiagnosed ADHD may face.
I think that the medication can help people with ADHD achieve things that they would really struggle with otherwise. (Note that the effects of the drugs are different to them compared to neurotypical people - you don’t get “high”.) But I’m not sure I agree with prescribing it to children. I think instead we should make schooling suit them better (and while we are at it, let’s improve it across the board - it is truly woeful atm).
> Certainly I don't have any ADHD diagnosis but a lot of the symptoms resonate with me.
The symptoms resonate with everyone because they are common experiences. The difference is a matter of degrees. You may procrastinate for a few days, but an ADHD sufferer will procrastinate for months and months.