I agree that i don`t get enough sleep over all. I`ve been working extra hours, hence im so determined to score better in my academics. the case is i used to get dizzy or sleepy, when studying more than 3-4 hours, often sleep in chair itself. how to prevent such lazy behavior, also how long an average man should sleep? is there any health benefit for taking naps in between of studies? also is that healthy to awake more than 18 hours a day with no sleep in middle?