Let me ask you this:
Your entire office is out at an all day "training." You were not invited. You are one of a handful of people still at the office with no supervision. Do you:
A) Work.
B) Sit at your desk but do no work. Maybe read a book?
C) Cut out and go home.
I'm going with option B today. Option A would make time go faster but Option C would invite karma to bite me in the butt in the form of my supervisor calling to "check up on us." So if you'll excuse me, I have some royal romances to read about.