For example, "You've just wasted five hours trying to prove to me that The Simpsons is still funny," or "You're sitting here at 3:30 a.m. arguing about when The Simpsons jumped the shark." Then they conclude that the other person is a loser with "no life" and might add that they "feel sorry" for them.
Few human beings being talked to in such a way can resist pointing out the obvious -- the accuser himself is sitting here arguing at 3:30 a.m. as well, and has been doing so for the past five hours as well.
That puts the first person on the defensive, and he has to point out his time zone ("It's afternoon here!") and other mitigating factors ("I'm just killing time until my girlfriend finishes work and comes here for sex!") before reasserting that the other person is, in fact, the pathetic one, and insisting that he feels sorry for them.
"I must not sleep until I have proven that Avery Brooks is the most insane Star Trek captain."
Usually these start off as side arguments, a "by the way" postscript after each side makes a point about what is wrong/right with The Simpsons, but eventually they grow and consume each post until there's one perfunctory sentence about the actual debate before an essay explaining point by point how much of a life they have, followed by a short story about how the other person came to the tragic day-to-day life they lead in their parents' basement. On YouTube and Twitter and other limited-space media, it's a little less eloquent -- usually just a random, disjointed jumble of cliched phrases, like "parents' basement," "Cheetos," "fat loser," "ur just jealous," "FEEL SO SORRY FOR U" and the like, that is mashed together to resemble a telegraphed message from a concussed toddler.
A tragic epidemic that underscores the need for child helmet legislation.