I'm about 11 months out from my projected FIRE date. I work in a unique situation where I don't really hide the fact that my goal is to retire early, but I've been pretty vague about exactly when that might be. Normally I allude to "sometime in the next couple of years or so." Timelines come up in casual conversation, but I keep it fuzzy and mention all the variables like what's going on with the ACA, how the market performs, etc. In short, I like to keep people guessing.
But they know that at this point, I do NOT need to come in tomorrow if I really really didn't want to. So I have a lot of fun messing with them and joking around, like when they assign me a new task, I'll say "OK I can do that. Assuming I show up tomorrow that is." Or when they inform me of a possible change in a thing I'm working on that they know is stupid and annoying but has to be done I say "No problem, we'll see how it works out. Or I'll quit, whatever." The best was one time I was walking by a boss's office (I have several) and another boss was in there, and as I passed by one of them calls my name. I turn around and go into his office and say "What?" in my cranky, pre-coffee morning voice. Then, brightening considerably, as if a new possibility has just occurred to me, I say "Oh, am I fired? Can I go home now?" (They both laughed at that one). Unfortunately, I think I've jokingly quit so many times, they probably won't believe me when I do it for real :)
(This is not something I would recommend most people do, but like I said my work environment is unique - we're all sort of volunteers assigned from other departments so we don't officially work for them, and these kinds of jokes/snarky comments aren't unusual and are clearly made in jest.)