I hear ya on the "everybody at once" phenomenon... We're usually two people working the desk. And if it's one of those calm days, as in "have you seen an actual patron in the last hour?" calm, the second one of us leaves for a break, or to go to the closed stacks (another building) or anything... It's like the locusts descending on Egypt. Everything happens at once: patrons, all of them with time-consuming questions, phone calls, computer messes, door bells...

And then it goes dead calm again. Weird thing...