Every day.
I mean there are certainly aspects that I will never miss. Getting home at midnight after a grueling rehersal and having to type out line notes and production notes, only to have to be back at the theatre for an 8am production staff meeting. I will never miss the lack of sleep that I got during productions -- I did the majority of my theatre stuff in college so when I would finally get done with all of my play notes, I'd have to start my school work. I'd go weeks sleeping no more than a couple hours a night--I could literally call shows in my sleep. I also remember several evenings where I slept in the green room or in our technical directors office because it was easier than going home!

But I did love it. It was constantly a challenge--thinking on your feet, using your imagination to get you out of jams. What do you do if the light fails to turn on when it's meant to? What if the tracks for the moving set pieces get stuck and your set piece is half way on stage and halfway off? What happens when someone accidently cleans (read throws away everything on) the prop table the afternoon before opening night? Remember all the while that the answer to every question was "the show must go on!"
I worked with a great department--they allowed the students (ie, me) to really just dive right in and they really helped hone our strengths and find work-arounds for our weaknesses. For example, I am musically challenged. I can't count beats, I can't carry a tune, I don't do music. Sure it sounds lovely, and I know what I like, but I that's as far as I go.
However, after two months on campus, I was asked to stage manage the dance concert. Every single lighting cue was written on the music sheets--which I don't fluently read. I was convinced that I was screwed when on of my favorite set design professors asked me why I looked so worried. I explained it him, and we sat down and brainstormed ways for me to call the show without reading music. Eventually we taped a rehearsal, and I spent hours watching it and precisely timing where each cue went with a stop watch. Every single cue was called off the stop watch for the entire run of the production.
It's strange because I definitely worked on much bigger and "better" productions after that (and I used that techique repeatedly) -- but that one really sticks out as one where I was faced with a huge challenge and the theatre staff helped me figure a way to over come it.
I honestly think that theatre is an integral part of any liberal arts program because it doesn't simply teach a subject, but putting together a production from day one to the final strike is about learning how to learn, how to recognize strengths and weaknesses, how to over come challenges, and how to work together to accomplish a united goal.
This is getting really long--I apologize for rambling on and on. One final thing--that favorite set design professor used to always keep our spirits up when things were going wrong on the set by asking: "Where you responsible for (fill in some world event)?" He usually said "100 kids dying in Africa today?" We'd answer no, and he'd respond, "well, it's nothing we can't fix then, is it?"