Lethargy

Got an exam in the afty. An audit. Totally no mood to study. Struggling from morn. Friends tell me , "Chod yaar, audit hi hai! Nbd mat le". A voice within says "When you've taken the course, why do a ship-shod job! Anyway, you've just a couple of hours left, give it your best". But, finding it impossible to shake off the mental lethargy. Boredom sinks in within minutes of study. Ever felt youself in the grip of a powerful lethargy? So strong, that inspite of your logical mind telling you that this moment is the very last to be lazy in, the lethargy refuses to loosen its vicious grip? How does one fight such lethargy!! All suggestions are welcome. [Not that it would help me for today's paper, tho! Guess it is a goner already! :D]