Monday was not a productive day. I arrived late, or rather, I did not arrive early. The time before things officially begin is usually the time I spend writing about the previous day, setting priorities, and generally processing everything that might interfere with subsequent focus. I missed all that.
Then as it happened, I had personal issues to attend to that took most of the day. My modest goal of listening to this week's cryptography lectures wasn't even met.
I suppose it is natural for days such as this to occur.