Education and intelligence aren't synonymous. The presence of ADD is separate from intelligence

Yes, this is partly correct. It’s not in lack of ability in learning with ADD or ADHD but in the ability to use/apply this knowledge. This is due to the area of the brain affected by ADD/ADHD.

Dr Russell Berkley has a long detailed conference you can watch on YouTube called “The importance of emotion in ADHD”. He explains how individuals struggling with ADHD or ADD can struggle with regulating their emotions. Also it is very common that when a child struggles with ADHD/ADD often a parent or even both parents do too.

I have actually seen this in a couple of my students where while the child was a challenge to work with, the parent was just as bad if not worse.