After reading Dr. Gregor's account completely, it seems like he's a masochist.
And I think that having this quality is what separates the men from the boys when it comes to med school and its completion.
To take the grueling hours of being on call, and on rotations (on your feet three quarters of the time), to take the abuse from attendings, residents, et. al., to have virtually zero social life, and to still have the drive to get that magic "M.D." at the end demands that one enjoy that sort of torture.
At first I was rather critical, but now I have to applaud him for sticking it out, and not dropping out, like some of his classmates did, and also for sharing his experiences with inspired (and perhaps misguided?) pre-meds.
My father who has been through this hellish process, told me about the hours involved, and he suggested I take the "acid test" to see if I'm really cut out for this sort of field. Incidentally, the MCAT tests for this ability as well. (if you scored much higher on your Bio subsection, than in your Verbal, then you're on good terms.)
BTW, the "acid test" is to try to stay awake for at least 40 hours straight. If you can perform this menial task, and still have a smile on your face, then you're golden.
-raindodger