I can tell you -- no, I didn't grow out of my disorder. My wife would back me up there. When I'm not making an effort to slow down, be deliberate, etc., it's very obvious. It's not so much a "coping strategy" type thing. That would be too clinical an approach. It's more that I just constantly strive to be professional, organized, clean, etc.
It's not perfect. My office/home are immaculate. My car? It's a pigsty.
I can definitely agree with you as to memory. Mine is terrible. You know what though? I work that to my advantage sometimes. The "I forgot" excuse (even if I didn't) still carries a lot of water for me where otherwise, it might not
I never forget big things (anniversaries/birthdays/deadlines), but I'm not so great with social engagements, whether I or my wife are responsible for my dinner each evening, etc. You can't be perfect. Perfect, in my opinion is boring. I think ADHD is part of what I am. It's part of my life. If I'm kicking butt in the grades department, I can't really argue with success. Sure, if I were taking some sort of medication, I might be closer to the top of the class. Sure, I might remember things, but I wouldn't be as "me" otherwise.