As someone with peer reviewed ADHD but not official diagnosis, what are friends gonna do about it? They can tell you, you're always late and it's annoying but that's about it. At some point it becomes just who you are as a person, part of your character sheet. If you're not planning to change and it's mostly under control (have job, life, etc), does it even matter to put a label on the thing?
I feel like a diagnosis in my 20's would've been useful. Now it's like I got me my coping strategies and they work pretty well. If I do or don't have ADHD doesn't really change anything.
And for anyone else reading, the leading symptom of adult-diagnosed adhd is saying and thinking things like "I don't get it, ADD can't be real, that's just how everyone is"