One, people will not believe you. "You're working?" they will ask incredulously. "On Monday?" And then, after a pause: "You know that's Memorial Day, right?" Salt in the wound.
Two, your favorite sandwich place will be closed. Worse, it will have a cute sign in the window reminding you once again that it is a holiday, dumbass, and you will have to get your lunch from the corner deli, the one with the stock boy who hits on you even though you are five months pregnant. "Hello, beautiful," you will hear him coo as you attempt to balance a package of mini donuts on your belly so that you can reach inside the fridge for a root beer, and you will wish for a moment that his fetish was just for helping sweaty women shop.
Three, the trains will still be running on a weekend schedule, which is to say, as slowly and irregularly as an obstructed bowel, and it will be hot, too--hot and fetid enough that for a moment you will look up from your magazine and wonder if you could, possibly, actually be inside someone's ass.
Four, someone on Facebook will soberly remind you why Memorial Day is called Memorial Day (Cliffs Note version: dead soldiers), and then you will feel like an asshole for being so self-righteously cranky about putting in eight relatively easy hours at the office (it's not like you're working in a coal mine, honey) and having to eat your sandwich on a regular roll instead of ciabatta.
That won't stop you from devoting an entire blog post to it later, though.
(Imagine Kevin Kline in A Fish Called Wanda: "Asshooooooooooole!")