I didn't think I had ADHD initially, I just assumed I was lazy and that everyone else just pushed through the mental challenges ADHD people has to deal with, but after a decade of nothing working I looked at the criteria again and realized it fit me. So then I went and directly asked to be tested for ADHD describing my symptoms. The science about ADHD isn't that good so sometimes you just got to do what I did, if you go in without an explicit goal chances are they wont find anything wrong with you or just try to treat the symptoms. Like I was depressed since trying to put so much effort and still failing to even focus was an extreme burden on my mental health, trying to treat that depression was hard, but now that I can focus most of that disappeared.

Edit: I think the biggest misconception about ADHD is the "the kid is loud in class, how do we make the kid stop being loud in class?" and thinking that disturbing class is the main problem the kid deals with. That was how ADHD started and what people know today is very biased in that direction, even among professionals. There seems to be very little information about ADHD and career prospects. Like lets say I want to build something, but my ADHD prevents me from building it, but with medication I can build it and I take pills to make that project into reality. That is what I care about, but most studies just look at how these pills improve kids behavior in class.