Stockdaling is the act or sensation of being somewhere and not knowing why you're there, or even who you are. If you get to the office and realize you have no idea what you're supposed to be doing, you're stockdaling.
Reference: Admiral James Stockdale, 1992 vice presidential nominee (with Ross Perot) who, in the vice presidential debate, led off with "Who am I? Why am I here?"
I got to work today and have no idea what the fuck I'm doing. I'm totally stockdaling.