What do you mean by “too late”?
Too late for a diagnosis? I was 65.
Too late to adjust to a diagnosis? To restructure your life? That’s up to you.
I was diagnosed 5 years ago. Like you, I was recently retired (more later on that one), and everything had fallen apart. I thought I was going nuts. I had so much time, but was getting less and less done. I’d always been messy and cluttered, but I’d always had the dreams of Someday. As in, Someday my condo will be neater, Someday I’d be more organized, Someday I’d read the books, write the letters, finish those projects, … etc.
I don’t know why the medical, psychiatric, and psychological establishments can’t think epidemiologically. We know there were ADHD kids in centuries past, we know it’s mostly hardwired, and we’ve known for almost 50 years that kids don’t often “grow out of it” (even if they look and even feel like it, they can have unrecognized symptoms and deficits). So it stands to reason that there are generations of undiagnosed adults out there.
I took an early retirement opportunity because of increased job pressures accompanied by decreased job performance and evaluations. Then I fell apart — poor executive function, couldn’t create my own structures to pursue any goals, even things I was historically good at (part of the diagnostic input). Moreover, I had a long, very complicated period of grief from which I am just now emerging. For newly diagnosed seniors, I think this is more common, but I also think that post diagnosis grief in adults is also more common than I read about.
Bottom line: you’re relatively young, you can look forward to 20-30 years of productive living. I’m not happy about having ADHD, but I know that any goals I have, any happiness available to me, can only happen by working WITH my ADHD, not against it. So, yes, it’s important to get a diagnosis.
BTW: your best chance for a diagnosis is with professionals who know what to look for in older adults. You need to ask around and maybe even travel. I live in New England, where pioneering work has been done in this area. I wasn’t at all looking for it, I was just fortunate to have a MSW trained therapist who suspected it and referred me to psychiatrist similarly attuned. His oldest patient he diagnosed was 72; a doc with the adult clinic at Harvard said he was working with a woman in her 80s.