Acronym for "first against the wall". Sometimes it's also lengthened to FATWWTRC (first against the wall when the revolution comes). The phrase is from Hitchhiker's Guide to the Galaxy, and is used most often to show anger or disapproval regarding abuses of authority.
Did you see those cops shoot that unarmed guy in the BART station?
While our lifespan is the number of years we will live, our healthspan is the number of healthy years we will have and our sexspan is is the number of years we will continue to be healthy enough to continue having an active sex life.
A lighthearted reaction upon receiving disappointing news of some sort. Usually something that isn't a particularly a big deal, esp. when it primarily affects someone else - sort of a mild schadenfreude. Sometimes doubled or tripled, and possibly said in a sing-songy voice for added comedic effect to imitate a muted trumpet, which is how the meme originated.
You didn't get any napkins with your takeout pork fried rice? Womp womp.