Doing well in one of these programs entails becoming a little afflicted with the so-called Stockholm syndrome. It's extremely difficult for me to actually concentrate for sixty hours a week, especially when simply studying, as opposed to actively completing problem sets.
The real danger lies in the fact that very, very few really enjoy grinding out this sort of time over the first-year material. None of us actively dislike it, mind you - this is a volunteer ship - but occasionally when I take a break I suddenly become aware of what else I could be doing, and it's very hard to force oneself back to studying for Monday's macro midterm. I think this aspect of graduate life is easier on the people who are married, late-20s, than on the fresh out of undergrad crew.
Completely blew a tire Friday afternoon, haven't been able to do a spot since. Here goes.