A mild inconvenience re: doctor's office

So, I had a doctor's appointment today.  When I was on my way out the door, my mother expressed surprise that the doctor was open today, it being the day after Thanksgiving.  I assumed it was just an unusual case. When I got there, though, there was no one there.  The door to the office was locked, and nobody answered when I knocked.  I called and left a message, explaining that I had showed up and there was no one there.

When I returned home, my parents were indignant.  Apparently, they consider it the height of rudeness to make a mistake about scheduling appointments, six months in advance.  I didn't particularly care, but I suppose they're entitled to waste emotional energy on a tiny organizational error affecting one person.

If they get this worked up over doctors' scheduling mistakes, it's no wonder they haven't got the time or energy to find out about what's going on with the Occupy movement.