While I am not a shrink, nor do I like pop-psychology, there is something going on in Sarah Palin's interview performances
that looks very much like a person who is under intense pressure and is putting every inch of her energy into trying to appear "in control" instead of imploding. This would explain the huge differences between the Sarah Palin who seemed to have a reasonable grasp on (her version of) reality versus the Palin who seems to have trouble remembering simple facts and political trivia.
Usually when I see people in this hunkered down mode with a fake grin plastered on their face, they are very near a nervous breakdown.
If this is the case, time will tell. It almost always does.