I am a senior and have probably pulled at least 20 all-nighters. In fact, for most science classes, that was my preferred method of study. I actually feel pretty good going into a test in the morning at 10 or 11 after studying all night. Now as for 2 or 3 in the afternoon, that is a different story. I usually take my test and then eat lunch and sleep for about 12 hours. I am somewhat of a night-owl though, I guess you could say. Anyway, I think everyone studies differently and you have to find what works for you. Now I do not advise studying like this. Obviously, there are benefits to cramming. Everything you need to know you just looked at for 12+ hours. However, there is the risk of feeling sluggish and you you probably won't retain as much. Also it is easy to fall into a habit of doing this (I am a prime example) and you won't change your ways until you just completely bomb a test. You end up studying all night for a test and then sleeping for the remainder of that day and then you get behind on more work and have to stay up for that test and so on and so forth. It's a vicious cycle. But most importantly you want to have better study habits for graduate school. Anyhow here is how I used to study for a test (for a test at 11 AM the next day): 1) Scan classmates notes for any classes I missed at 5 PM 2) Print off/organize all notes and practice problems 3) Eat dinner and make a run to CVS to pick up an energy drink or coffee 4) Watch TV for about an hour and contemplate why I ever did this to myself while also repeatedly telling myself I'm never doing this again 5) Begin reading and making notes of chapters in the book at about 8 PM (I have sometimes already did this and simply review the key points) 6) Review lecture notes chapter by chapter 7) Practice problems, practice problems, practice problems 8) Review any questions I have until about 9 AM 9) Shower, breakfast, coffee, and some Mariokart until 10 AM 10) Review questions with teacher until test time 11) Ace that bad boy and enjoy the time off I have until my next all-nighter and then repeat hating myself, etc.
Again, I do not advise this, but I go to a pretty respectable liberal arts(ish) school in the midwest and I have a 3.96 as a chemistry major. I am pretty intelligent but have never considered myself a genius or anything. Most people think I don't study but the reality is I actually study more than most people after adding everything up.