I've got another comment in this thread with several links. In general if you resonate with a lot of that stuff it's worth getting an evaluation.
I believe that people should no longer treat AD(H)D as an acronym. It isn't accurate to call it a chronic "deficit of attention" and hyperactivity isn't necessarily a symptom. It's unfortunate that the name has to stay for the purpose of recognition in the face of the new evidence we've gathered in the past few decades.
Interesting. I feel like that fits me to a T.
If I'm not interested in something, it's very hard for me to get in to a focused state of mind.
Why did they disqualify you based on being able to focus on things you like?
Lack of knowledge on the part of the person assessing them. Some people who go for diagnosis wind up going to people who don't specialise in it and they wind up being told these kind of things.