I think I was only a good student for three years, but I even doubt that assertion. My first three years at Berkeley I was very studious, but I think a great deal of my success in the courses during this time was due largely to my pre-existing familiarity with the subject matter, where most of my peers had quite little. After my year in Sweden, with the newfound sociability of the co-ops and a wholly relaxed attitude due to a year of travel, it was nearly impossible to be so studious. At this point I'd simply refuse to do the 36-hour hacking sessions, cramped in the basement of Cory Hall, that the EECS program periodically requires. One of my current roommates hasn't received anything less than an A- since eighth grade. This sort of thing puts me completely to shame.
Good study habits are so hard to keep, and now they are obligatory. My professors this semester are not teaching from any textbooks (not that there aren't good text books to teach from), which makes attention to lectures, something I've never been particularly good with, rather important. My math methods lecturer deserves some kind of prize for his lectures, but I am vastly less enamored by the QM and EM lecturers, and in those cases would prefer to be following a text, on my own.