"Most people can recall a kid from grade school who couldn't stay seated, who talked out of turn and fidgeted constantly, whose backpack overflowed with crumpled handouts and who always had to ask other kids what the homework assignment was. Those kids weren't bad kids, but they seemed to have absolutely no self-control, no internal disciplinarian to put a brake on their impulses, to keep their attention focused. Not surprisingly, they were almost always lousy students as well."

Heh, I think I was that kid - but a pretty good student as well. My grades were relatively poor (because I forgot or didn't want to do the homework), but it wasn't uncommon for me to have the class high on exams.

Fortunately, I had one of the highest set of test scores (SAT/ACT/AP) of my class and that more or less made up for the poor GPA and class rank.