Three...
It's cannonballing steadily towards that final post, and I've discovered that I've stumbled blearily through the desolate plains of conventional tiredness, and flailed my way into the calm, clear-eyed Uber Superlative Sleepiness beyond, which involves such vast amounts of tiredness that the brain actually interprets it as a normal awakened state. Consequently, my head feels all airy-light and fluffy (now that my brains are lying in a modest puddle on the floor), and if you knock my head, I am likely to echo, somewhat like a wooden log.
And I'll promise to sleep like one, too.