work fog
That not-all-there dreamlike state you're in while at work. Typically diminishes as soon as you leave work. It tends to diminish slower on Mondays and fastest on Fridays. Common symptoms include endlessly staring into space and answering any and all questions with a simple huh what did you say.
Hey man {peers over cubical wall} you don't seem like you're all here today. Oh he's just in work fog.