I agree with Fooze on this one about you seeming like your describing hyperfocus, If I am alone and I know nobody is going to be home for a few hours and I am feeling motivated, that is when I can get my greatest work done. Like the other day my dad was out of town for most of the day golfing, so I went out to try and solve why my truck was having issues with the transmission. It was simple to actually find out but because he was not home to distract, my attention was in the zone I would say for a good 5hrs. The world around me did not matter and I heard nothing or saw nothing in my head but the wiring in front of me. I found the problem, fixed it, then one thing led to another after that, tieing up some loose ends of my truck wiring, and deciding what part of the wiring I want to fix next etc.

The one thing that did snap me out of it though was a random truck driving up the street and stopping every couple houses. I think may have had sticky fingers on there minds. They got up to my house which had the garage open, stopped in front of it then surprise I jumped up from my driver side door and shined my light in there faces. needless to say they left and have not seen them since. My unpredictable hours of action puzzle all

Also to, you said you do not feel like you're driven by an engine, that is not always the case either where you feel like you just have to do something even if you're tired, not everyone has this symptom either, sometimes people just get the inattentive type of adhd which does not include the hyper aspect. Some only get the hyperactive adhd, and some get adhd combo type.

Me for example, I am not necessarily hyper, I can be, but if I am in a class or somewhere I have to sit. I am constantly bouncing 1 leg or both, tapping a finger, looking around, I never sit still and tune unless it is really interesting. Also for me, if I do not at least have some part of my body moving I feel like I will explode from the tension/ energy building up from sitting.