I think I made an entire thread awhile back about how some people couldn't see the big picture or deal with general concepts, but could only comprehend specifics.
I would say "Can't see the forest for the trees" but you would only understand that statement if I identified the exact type of tree, it's height and width, where the observer was relative to the forest and the trees, the temperature that day, the moisture content in the soil, the observers eyesight in terms of was he wearing glasses or contact lenses, what was the age of the observer, his nationality, skin color, his preference in food and movies, the observers education level, does he also believe that Martin Lawrence is the greatest actor ever, etc.. Whoops, etc.. is probably not specific enough.
Example of someone that obsesses on details and can't comprehend a generalization:
Forest Ranger: There's a Bear, run.
Non-Generalist: Could you give me the GPS coordinates.
Forest Ranger: He's over there (points). You need to run this way (points).
Non-Generalist: I can't run without the coordinates. You must give me the coordinates of the Bear, our current location and all of the exit points.
Forest Ranger: I'm outta here.
Non-Generalist: I will need your badge number and your bosses name and phone number. I'm going to report that you did not provide me with GPS coordinates.
Bear: Rarr.
Non-Generalist: I'll need you to state your intentions. I also need to know the size of your claws and teeth in case you bite me, then you can be identified later.
Bear: Yum.
