Suddenly and inexplicably not giving a fuck at work and life in general. Often caused be completing a huge project or being blasted by a superior. A reference to the 1999 Mike Judge comedy 'Office Space', in which case the cause was hypnosis.
Employee 1: "Now that the Milkowski case is over, I have the best case of Office Space Syndrome. Let's grab a Beer."
Employee 2: "It's 9am."
Employee 1: "DGAF Nation!"
Employee 2: "Fuck it, I'm in."