i received a pm, but the other instructors here have done a nice job of answering the question.

this:

Brian Galvin here at Veritas wrote about when students think that the test that they are about to take is "THE GMAT" when in reality it can be retaken and so less pressure will be there if you think of it is "A GMAT" with others to follow if necessary.

i like this phrasing. i like it a lot.

among my favorite analogies for it so far has been "dress rehearsal" (i tend to think of things more in terms of analogies to the arts, for whatever reason) ... but this one is a nice, compact way to express the idea that will be immediately understandable to anyone. well done.