This poll is primarily for those very serious ones who intend to do graduate studies/earn their phD or are already past that point. How many hours of study per day on average do you do? This includes being in class, provided that you are actually using your brain deeply in class (as opposed to blindly taking notes without understanding what you are writing, or just socializing at school). For those who are not students, this can include your hours of research (but not hours in teaching, marking, and other non-research type services). I clock in at 12 hours per day, and love it. The other miscellaneous acts during the day (eating, showering, talking people, etc...) are done only during my breaks from studying. Thus I schedule my studying in such a way that only when I need a break from studying do I do the other things, including going out, but those can only occur within a window of 2 hours at most because by then I am ready to hit the books again. If I am ever stuck somewhere for more than 2 hours, then I have my textbook and pocket-sized computer handy. Solving a problem in my mind while doing other things that I am forced to do (e.g. driving) usually hasn't been a problem for me.