Yeah, tell that to me when I'm waiting for Revit to open up the first time. Another usual gotcha I run into in a class setting is trying to open Revit several times when you become convinced that Revit is not loading after you double clicked the Icon on your desktop.
When you double click the icon you get a little hour glass for a few seconds and then, poof!...nothing, no hint of Revit loading and you start thinking, "Did I really double click or was it a single click" and "Did I see an hour glass or did I imagine it?" So you double click it again and suddenly Revit appears again and shortly afterward another session appears and, if you aren't a lucky sort, so does an error about licensing.
This can be lots of fun when a classroom of 12 opens up Revit before I get a chance to warn them. One poor soul tried to open Revit twelve times before I interupted his efforts. At least the other eleven sessions opened up pretty quickly after the first....
So the moral of the story really is patience IS a virtue AND that hopefully Revit will get better at telling Windows what it is up to so we don't start to doubt ourselves!