And then there were none

Yesterday I had one of those first-week-of-school moments of panic, when I looked up and realized I was the only person in the library.  It didn't help that several classmates, present minutes earlier, were suddenly all gone.  What am I missing?  What part of the schedule do I have wrong?!  So then of course I had to run around peeking into classrooms looking for the phantom class.  This may be further evidence that I am infected by epistemology.