Sometimes it's better just to give up

You know how, in the evenings, you hit a wall? The exhaustion peaks, the yawning is so non-stop that tears are running down your cheeks, and you're getting nostalgic for things you might miss if you go straight to bed.
But it you fight the power of lethargy and manage to stay awake (if not alert) for about half an hour, you can then stay up 'til all hours of the night without yawning.