I can has cheezburger ... and pathos?

To try to understand, I turned to Bob Mankoff, the New Yorker's brilliant cartoon editor. After all, a lolcat is just an image with a caption -- in other words, a cartoon.

The first reason sad lolcats can be so powerful, Mankoff suggested, is their comedic structure. The meaning of a lolcat is rarely straightforward -- rather, there's a punch line of sorts, a layer of meaning you have to think about for a moment in order to grasp. So the punch line, the same thing that makes the lolcat funny, is what makes it sad. You could call these tragic strips.

The best example I know of this kind of cartoon is one by Charles Addams that depicts a male and female unicorn standing on a sliver of land in the rain as Noah's Ark sails away.  Having arrived too late, all the unicorns can do is watch the ark recede into the distance as the waters rise around them. The image conveys so much regret -- the idea that we were so close, that we could still have these magical creatures among us today if only we'd been more patient. It's the sadness of missed opportunities.

But the unicorn cartoon still has the structure of a joke. You have to "get" the extra layer of meaning, grasping that the unicorns aren't, say, marooned on a desert island, but standing on a mountaintop as the floodwaters surge around them. "It's not just sad, because something that's just sad -- someone being killed, run over -- we know what that feels like," says Mankoff. "Here, you're using a mechanism that's usually involved in humor: the cleverness of getting it."

A second major factor in the poignancy of the sad lolcat, I would argue, is the use of animals. The comic form is generally a prophylaxis against sentimentality. By articulating profound feelings through cats and marine mammals speaking garbled English, we're able to shroud genuine emotions in pseudo-irony -- which means those animals can evoke deeper emotions without fear of mockery or cheapness.

Animals are also childlike and helpless. When we see a cute little dog in a New Yorker cartoon, it triggers the responses we have toward children. Cartoon dogs are childlike creatures: They're cute and have big heads, big eyes, exaggerated, childlike features.

Of course, to express human emotions, you need an expressive face. "It's cats, not scorpions," says Mankoff. "It's cats, not rats. If somehow on YouTube there was a rat flushing the toilet over and over again, we wouldn't think it's too interesting."

It is because animals are able to move us so powerfully that many tragic strips use animals instead of people. In one New Yorker cartoon, a dog is lying on the couch, while another dog, his therapist, sits in a chair and takes notes. "They moved my bowl," says the dog on the couch. The message isn't really about the moving of bowls at all, but about our problems in life, our frustrations, our sense of being victims.

"The animals aren't animals at all, they're stand-ins," explains Mankoff. "They're hybrids we use as devices to talk about the feelings we can't name in other ways."

The same is true of the sad lolcats and the lolruses. Consider LolSecretz. It's like PostSecret.com -- which publishes anonymous bathroom-wall-variety confessions ("I had gay sex at church camp," "I only love two of my children," etc.) -- except it uses images of cats. In one, a black cat says, "I just wishes I wuz white." In a third, a world-weary cat with dead eyes gazes longingly at a knife, saying, "i killed mahself 6 timez ... 3 to go."

Just as the dogs in the New Yorker cartoons don't represent actual dogs, these cats don't represent cats at all, but people. By using cats, icanhascheezburger can access themes more tragic and poignant than it could using people. You wouldn't enjoy a comic of an actual person fingering a blade and contemplating suicide -- but when it's a cat, you can accept it. You can even laugh.

And that's the real answer to the puzzle. We've gone from cats as cats, to cats as scheming rascals, to cats as human beings. The sad lolcats represent people. We have seen the lolcats, and they are us.