Because I can't muster the energy to get up today.

"Fat Charlie was thirsty and his head hurt and his mouth tasted evil and his eyes were too tight in his head and all his teeth twinged and his stomach burned and his back was aching in a way that started around his knees and went up to his forehead and his brains had been removed and replaced with cotton balls and needles and pins which was why it hurt to try and think, and his eyes were not just too tight in his head but they must have rolled out in the night and been reattached with roofing nails; and now he noticed that anything louder than the gentle Brownian motion of air molecules drifting softly past each other was above his pain threshold. Also, he wished he were dead."- Neil Gaimen


That's a very accurate description of how I feel today.  The question is, was last night worth it? Ask me tomorrow.