I don't even know for 100% sure I have it but the last time I tried to talk to a professional they basically just wrote me off because my grades were good as a kid, I understand part of the diagnostic criteria is symptoms presenting themselves in childhood but to be honest I got by just fine without studying or paying very much attention.
Does anyone have experience with this
Tell them this — you did well enough in school despite an inability to focus or pay attention.
That was me too. I was able to focus on subjects I liked and have a great memory overall, so I did well on tests despite developing zero study habits, I'd always forget to do my homework at home so I'd always be doing it the period before it was due, I lost my planner within the first 3 weeks of the school year every year without fail, and I'd never remember to write anything in it or check it anyway. My backpack and locker and school desk were always an absolute disaster , I couldn't keep subject binders so all my important papers got crammed into one disorganized folder, I was constantly in trouble for never cleaning my room, and no matter how much I wanted to improve I absolutely never could.
My disorganization made college really hard but I managed to get through it purely with cramming and all-nighters to do an entire semester's worth of coursework or projects at once because I cannot remotely begin to start anything unless there's an urgent deadline.
Any decent psychologist should consider this too and recognize these behaviors as being consistent with ADHD