The grating thing about unannounced or ongoing tests is not so much the surprise factor as never being quite sure what it is, exactly, that's being tested.
That suspicion intersects with another, that almost everything in and about life these days -- pick something, anything at all -- is really just meant as a test of our sanity, of how much we can take, how much craziness we can jam into the claustrophobically-closing, finite spaces all around us, and how much lunacy we can tamp down and cram in, into the potentially infinite space between our ears.