There's actual science behind why a two sentence YouTube comment can make you laugh harder than the ten minute video sitting above it. Psychologists have a name for this effect. It's called the incongruity theory of humor, and it basically argues that our brains find something funny when reality suddenly veers away from what we expected.
You watch a moose knock over a canoe and brace for chaos, then someone in the comments deadpans that the moose was simply reviewing the canoe's stability rating, and your brain does a little double take. That gap between what you expected and what you got is where the laugh lives. Researchers who study this theory point out that the twist has to land fast, because the longer a setup drags on, the more your brain settles into expecting the punchline, which drains the surprise right out of it before it even arrives.
That's also why the internet has always rewarded short form comedy. Long before YouTube comment sections became their own genre, Twitter's character limit forced people to trim every joke down to its sharpest edge, cutting out anything that wasn't pulling its weight.
Comedians have always known that pacing, what's technically called comic timing, can make or break a line regardless of how clever the words are. A joke that needs four sentences of throat clearing before the payoff usually isn't a joke anymore, it's a story. The funniest online comments skip the throat clearing entirely and go straight for the punchline, trusting the reader to fill in the rest without any hand holding.
Then there's the community angle, which YouTube comment sections do better than almost anywhere else online. Watching a video is a solitary act, but scrolling through the replies turns it into something closer to a group chat with strangers. Someone drops a pun so bad it loops back around to brilliant, another person builds on it, and within a few replies you've got a whole bit developing in real time underneath a video about, say, a squirrel stealing a sandwich.
Writers who study the format have noticed that certain formulas keep reappearing because they work so reliably, things like the fake time stamp pointing to a moment that doesn't actually exist in the video, the comment written as if it's a message sent back from the distant future, or the reply that reads the room so well it ends up with more attention than the original post itself. Even long running roundups of these moments (like this one) keep finding fresh material because the format never really runs dry, and every new video gives the internet's amateur comedians another blank stage to work with.
A lot of the best comments also lean on being relatable rather than clever for cleverness's sake. Self deprecating humor tends to land harder online than showing off ever does, because admitting you also microwave your coffee four times before finishing it makes you likeable in a way that a perfectly crafted zinger sometimes doesn't.
