Our hotel shuttle left right on time and we were checking in by 4:15 a.m. The fun started when we we went to TSA Precheck. It wasn't open and we were directed to an entry a couple of minutes walk away.
Those employees directed us back to one on the another side of Precheck, which we learned opens at 4:30 a.m.
Rather than waiting 10 minutes we walked on to the regular line which was deserted. There an employee told us we had no Precheck privileges (as at some other airports) so it was off with the shoes and the whole works.
We then made our way to the automated train, and boarded one that said "all gates." The train on the other side was "out of service." One small detail: we rode out to A and C Gates and then headed back to the Main Terminal. Others were equally confused but we got off and got on the train arriving on the other side that was now going to B Gate, our boarding area.
If you are already on, there is no announcement until the door has closed.
Anyway, here we are. We're guessing Dulles just starts to come to life at this hour and we caught it at a bad moment.