ADHD can present in may ways. When I was young it presented as hyper-focus. I would start reading a book and the entire world would disappear. I was unaware of anything but what I was reading. People could come and sit beside me and I wouldn't notice. Sometimes they would ask me questions and apparently I would answer them - all without realizing it.
As I grew older it gradually changed to the more usual presentation of symptoms. One way it manifested was during love making. I would be getting into it and then I would get distracted by an errant thought and bang all the arousal was gone and we'd have to start all over to get it back - a patient partner really helps. Years went by before I was diagnosed and then it suddenly all made sense.
One thing I can tell you is to get a doctor that is comp0letely up on modern treatments - things have gotten very sophisticated. Don't just settle for Wellbutrin plus plain dex or ritalin... there a better alternatives. Meditation can help too.