Female Science Professor has a great take on what our students think when we're not in the classroom: "Perhaps now there is one less student who thinks that when professors are not teaching, if only for a day or week or two, they must be on vacation or, at the very least, in a state of suspended animation in their professor pod, waiting to be re-activated just in time to put on their professor suit and head to class via the secret professor tunnels."
If I thought of my professors at all as an undergraduate (and I usually didn't), this wouldn't have been too far afield, and I'm assuming things haven't changed that much except that I hope students today are less clueless than I was. I did get a glimpse of this attitude one time when student stopped dead in his tracks as he saw me going into a local fish market: "You shop HERE?" he gasped.
Students have their own lives and their own personal dramas, and I've never thought that they would be terribly interested in ours, nor should they be. Students and professors are in the classroom on shared ground--our interest in literature or writing--and there's never enough time to discuss those, let alone personal lives. (All right, if you want to be cynical about it, we're there for another shared purpose: their need for 3 credits and my need to provide those credits. I prefer the former explanation.)
But if you're absent from a classroom, they do see it as a vacation, or so I've gathered from comments over the years, just as everyone outside academe assumes we spend the summer lying in the hammock with a cold glass of lemonade. So now I do explain what conferences are and why we need to go to them. There's the exchange of knowledge, of course, and learning about new scholarship and all that. Sometimes I tell them what I'm working on, but briefly, since their attention span will run out waaayyy before my enthusiasm about talking about my project will. I figure that the classroom ought to be about the subject matter, the students, and--a distant third--me, in that order, and any time spent talking about my work is time that isn't being spent on the first two parts of that equation.
What arrests their attention when I talk about conferences, however, is the practical side of things. We sit in small, stuffy rooms from 8 until 5 every day, listening to people read papers to us, even when the weather is nice outside. In short, during the span of a conference, we're doing some of what they do every day, except that we take turns in teaching others. It doesn't sound like a vacation, although I tell them that we do enjoy this, but by that time, I'll bet they think the professor pod option sounds mighty fine by comparison.