You may make a very dangerous mistake by listening to the opinions posted here. FR has a history of ignorant idiot enthusiasts who don't "believe in" ADHD even though it was clinically characterized about a hundred years ago, when mothers stayed home, fathers were disicplinarians, and there was no TV.
Find a psychiatrist who specializes in spectrum disorders. From the brief description you gave, your son sounds more like Aspergers than ADHD.
I thought the same thing when I read that- child sounds aspie or autism spectrum. Which ADHD behaviors are part of the package.
Hope OP goes and gets a true medical diagnosis, it could be a life changer (for the better)