I'm sorry, the cleric is busy
You wargamers out there in LJ land will immediately understand this.
I was playing Baldur's Gate today (a computer version of Advanced Dungeons & Dragons), and I kept getting into a very limiting scenario. My party was getting beaten up in fights that were incidental to my overall goals, causing me great delay and frustration.
Ordinarily, one goes into an adventure situation full up on hit points, spells ready, healing potions stashed. The goal is to expend what you have to (but no more) to keep functioning. Once one crosses the finish line, you heal up, after which, you go rest (to recover healing spells) and/or go shopping for magic (as in, healing potions).
But sometimes, like today, you're out in the wilderness, and you've only got what you've got on you -- until further notice. And your party gets so beaten up, that after they rest they still have to expend all the healing spells they've got to be fit for adventuring that day.
Which means, no margin for error.
Well, I feel just like that. By the time I've got my tired, creaky body in motion on any given day, there's almost nothing left to deal with stuff getting thrown at me. And the monsters -- I mean, work -- just keep coming. I am overwhelmed, out of resources, barely keeping up. Unless the DM has mercy, it wouldn't take much to make me want to run away.