There is a moment reached at night
When energy is overspent
And time suspends itself aloft
And no one quite knows where it went.
The time it takes to understand
That one's brain has reached a place
Where nothing else goes in or out
Is quite akin to empty space.
All light and knowledge drops itself
Into a void consuming all;
Bundles of despair and sleep
Collect in drops, release, and fall.
This unknown dark of empty space
Is not quite empty as it seems.
What exists in clouds of dark
Is quite unknown except in dreams.
And so the weary night owl falls
Out of his own intended flight
Against the pull of unknown voids
And gives in wholly to the night.
postscript
...which is exactly what happens when you can no longer keep your eyes open over study material for an astronomy test.....