Suddenly your inbox is overflowing with messages from people you've never met expressing their intense interest in your subject.
And, driving across town in the morning takes twice as long as it did just a month ago.
And, your laptop takes a tumble and breaks a hinge.
Plus, the photocopier at work seems to be involved in a work action (but, curiously, can't be bothered to make a placard to announce its grievances).
And, the combination-locked computer-enabled classroom is suddenly without its all-important doorstop (which lets students get into the classroom), so you're reduced to cramming one of your sandals under the door.
Good golly, it must be the beginning of the school year!