Within 4 walls

Does anybody else out there have a day like this, when they know what they should do, they want to do what they should do, but they cannot do it because there is some stupid, niggling thought at the back of one's mind that keeps zapping those neurons and interrupting any attempts at learning? And no matter how much ice cream you eat, rest you take, music you listen to, nothing adequately smothers that one niggling, idiotic thought that threatens your future (okay, I'm exaggerating, more like the exams, but then again, at the moment exams are the future). And you continue to be distracted, knowing full well in your heart that tomorrow when you awake and find yourself so behind in that revision schedule you'll begin to quake and curse yourself for your slovenliness and lack of self control.

Well, today is one of those days.

Anybody else out there has them?