One thing I've learned in college is that you have to learn to set your own pace. Do not let other people's study routine overwhelm you or pressure you in any way. You have to focus on yourself and know what study habits work best for you because stay-up-all-night reviews are not for everyone. Do not feel guilty when you reward yourself with an 8-hour sleep, when you make time to hang-out with your friends, or when you finish a season of your favorite TV show. You can do all of these things as long as you know how to prioritize and when you should be studying. It is all about balancing work and play, or in our case, study and play. Do not exhaust yourselves too much. Don't study too hard. Study well. Study wisely.
PS. I have nothing against students who spend all their time studying, if all-night study sessions work for you then you may happily do so.