Short answer -- your friends have 6 hours/night more study time than you. My bet is that if both of you studied the same amount of time but you got 8 hours and they 2, you would perform better, assuming your study habits are equally good.
What I've learned is that sleep IS important -- it's better to sleep than not to sleep. HOWEVER, staying up late and memorizing material over and over is definitely worth more than sleep is (for recall purposes). If you don't have time to review X due to sleep and X is on the exam, then you definitely lose out, right?
I have been an 8 hour/night sleeper. The attitude there is that I must get 8 hours of sleep, even at the expense of other things, such as making sure I obsessively know every single little fact in the material. 2 hour/night people care about memorizing every last detail of the material, at the expense of sleep.
I found I memorized best by memorizing 10-12 pages of notes so I could recite them from memory, recalling them all lying in bed, then recall them in the morning and touch up throughout the day. You just can't squeeze that in if you get 8 hours/sleep on an overloaded schedule!
What I've learned is that sleep IS important -- it's better to sleep than not to sleep. HOWEVER, staying up late and memorizing material over and over is definitely worth more than sleep is (for recall purposes). If you don't have time to review X due to sleep and X is on the exam, then you definitely lose out, right?
I have been an 8 hour/night sleeper. The attitude there is that I must get 8 hours of sleep, even at the expense of other things, such as making sure I obsessively know every single little fact in the material. 2 hour/night people care about memorizing every last detail of the material, at the expense of sleep.
I found I memorized best by memorizing 10-12 pages of notes so I could recite them from memory, recalling them all lying in bed, then recall them in the morning and touch up throughout the day. You just can't squeeze that in if you get 8 hours/sleep on an overloaded schedule!