I don’t know if it’s just me, or if as a grad student you just become used to sitting at attention through three-hour classes several times a week, but it was fascinating to sit at the back of a room this afternoon during a presentation and watch a class of undergrads (who were, for the most part, polite, attentive, and non-sullen) start to shift around and squirm in their seats and lose their focus 35 minutes into it. (The presentation was terrific, so that wasn’t the issue.)