I had known I probably had something like that, but I tended to downplay it, trying to pass as normal. I knew about autism and "Asperger", as it was called then; it gave me explanation for my weirdness and the first hints at how to overcome it (for example - I'm introverted by nature, still am, but have relearned since the early youth to be very outgoing and communicative and to enjoy the presence of other people. I don't know how I managed that. Also, I've learnt how the people are supposed to be "read" - I was annoyed at being perceived as having no empathy, so I kinda bruteforced it, memorised actions and thought processes, from art, psychology, from being nakedly honest with other people...). I too was surprised at the ADD, but it made sense in retrospect, yet I found that I've been actually somewhat self-medicating as well.
Furthermore it was about the time when everyone was in love with Sheldon and Lisbeth Salander and liked to self-diagnose as "Asperger", which was the ultimate cringe and something I wanted to avoid, so I pretty much never told it to anyone and didn't want to point at it too much.
My psychologist actually asked me whether I want the "official" diagnosis, that it is quite plain to see to any mental health professional worth their salt that some of the mental processes and mannerisms do scream "spectrum+ADD", in some combination, however it is not completely obvious to most laypeople (apart from me being different somehow) ... and with me being high functioning for starters and having spent most of my rational life trying to pass as "normal", to be as normal as possible, I really fucked up the symptoms to the degree where it would make further testing to make some heads or tails out of it and even then I'd probably fall into that type of idiosyncratic manifestations that are useless to anyone, as a diagnosis or as a specimen.
Thing is, I was there for a different reason (I'd had my first and largest bouts of panic attacks recently that were ultimately disconnected from this), - so I asked how it could help me to be normal, she said not much, I said well, thanks for the clarification, let's address those things that are a problem.
But I fully realise I won in the lottery - I'm the "eternal gifted child", the old school Aspie, the "savant". I'm atrocious at small talk and often am very open and honest, which may freak some out, I do abhor shallow relationships and conversations and therefore I don't have as many friends - but those that I do, those go deep. The family life is probably the hardest challenge so far - after being together for 14 years, sometimes it's really frustrating to be getting the best of me ("how could you not see that and that") and being there for the children with my diminished mental capacity for children is hard (especially since all are in some ways ... "spectral"). Still, I had it extremely lucky, so I can't really compare it with the experience of other people.