The best I can come up with is that the spaces inside my head are echoing more than usual, which sounds all emo and poetic, but is as close to an objective observation as I can come up with.
If I were being emo and poetic, I'd say that the inside of my skull currently has white marble floors and great arching vaults of ivory, a cross between a library and a cathedral, and whenever the thoughts trudge across the floors, their footsteps echo back and forth mercilessly, until even the bits that ought to be silent keep on ringing, even when the thoughts have completely given up and are simply clustered around the doorways, sulking.*
I don't feel particularly BAD, but definitely rather off. I was planning on partying tonight, but I think I'm gonna hang out with a video game and vegetate for a bit instead. There's a webcomics coffee clatch tomorrow, and that should provide me with some vital getting-out-of-the-house time.
Maybe I'll take a bubble bath.
*A thought, in case anyone is interested, is swathed completely in cloth from head to toe, and looks rather like the offspring of a tragic liasion between a Ringwraith and a jawa.