fatigued without exercise !

the chapters on work physiology taught me a great deal about the body's dynamic work rest cycle and it's response to varying degrees of exertion...my body seems non-conforming to the laws followed by other homo sapiens sapiens.. one week of um..predominantly inactivity has ended in me being fatigued and tired this thursday though i don't know from what!! today i was suposed to rush through some v.important portions of pharmacology and yet..what did i do?? watched tv indolently..slept...ate breakfast and lunch.slept..went to a nearby mall at the insistence of friends....then had a book on my hand but was basically dozing off.. and then ate dinner and now im sleepily writing my second post. god, why am i not endowed with a fighting spirit, with steely determination and good concentrating power(im talking about studying .. otherwise itz fine)???at this rate , im beginning to wonder about my future prospects..days floating by..exam on 6th and i havent even finished half of that tiny summary book which im following (btw, i had aimed to study from an uncomfortably thick volume of the main text..as usual,had to chuck that plan and got a book that explains nothing but has shortened each big chapter to 5lines)....i hate my lackadaisacal attitude!!O.K. writing this post has livened me up a bit. maybe i Can force myself to read one page bofore flopping on the bed and immediately dreaming up an impossible dream. goodnight!