When all of a sudden you realize something terrible has happened to you, it feels like being slapped in the face with a wet fish. In instances where you gain this insight right after waking up, you have obviously 'slept with a wet fish' only to realize what a fool you've been after you wake up.
When I woke up and realized those conmen had tricked me out of a lot of dough last night, I really knew I had slept with a wet fish all night long!
Referencing well-known medical drama 'Grey's Anatomy,' GSWI is the sudden onset of remembering events, usually regrettable, that occured previously while heavily intoxicated, just as the late George O'Malley remembered his adulterous sex with Isobel Stevens.
"Oh no, last thursday night! George slept with Izzie."
"Ohh no, what did you do? ..."
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.