A very annoying YouTube trend which involves editing a comment to make the replies of said comment look nonsensical and unrelated.
It sometimes can be used to try to make themselves not look like an idiot.
Comment: *An actual joke*
Author of comment: Nah...this looks too shit of a joke, lets change it!
Comment: I edited the comment so that the replies don't make sense
Person 1(Drunk): Haaaa...loook at thaat raaiinbooowww, ittt''s glooowwwiiiingg!
Person nr 2 (Sober): Excuse me, but firstly there is no rainbow, it's dark, secondly, what you're saying doesn't make sense! and thirdly, you're drunk.
While originally used by professors of quantum physics to make sure students are understanding what they are talking about, it has evolved into a not so subtle way of insulting someone's intelligence.
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.