Not to 1-up everybody, but I strongly suspected & brought the suspicion to a psychiatrist at age 43. He felt unable to to confirm, deny or somehow check.
At 46, finally a referral to a clinic by my GP, who believed it. No appointments available though, not even in the distant future.
1.5 years later, I'm in the process of getting checked, and it looks like I'll get a "yes" or "no" (very probably "yes") within a few months.
Obviously a dropout, too, but I managed to get a fraction of my potential due to an unexplained (to this day), 5 year lasting obsession with IT in my 20s, which caused me to study frantically day & night. Came and went, but a lot of it is still relevant.
In the past 20 years, I managed to land fat jobs over and over again, but like relationships and everything else, the fuss around the work itself gets "too much" and I quit after 6 - 18 months.
That weird 5 year study-frenzy was a blessing overall, but it also got me to think I was just an assclown before and after, rather than having a medical condition.