Believe it or not, I'm not a big fan of night shifts.
Rereading my entry from last night, I got to thinking about night shifts and how you feel during each successive day:
Day 1: Usually not fun but at least you have the energy of being fresh.
Day 2: The worst day of night shift. You're still recovering from the night before, and your sleep schedule is still not adjusted. Usually whichever of your muscles and joints have a tendency to hurt will start hurting a LOT during this shift.
Day 3: The least painful, in my opinion. You've sort of gotten in the groove of sleeping days and working nights.
Day 4+: Constant exhaustion from keeping up a schedule that's so wrong.
Of course, I've never done more than two weeks in a row of a night shift. Maybe it eventually gets better. I read about some study where a person adjusted to glasses that flipped the world upside down, so if you can adjust to that, I guess you can adjust to anything.