One of the easiest ways to analyze the appeal of digital memes is to understand the meme idea in general, and what it's supposed to do. Transference of cultural knowledge in small chunks through imitation is the basic idea behind memes. Richard Dawkins was the first to talk about the idea in detail, but historically, most meme theory has been focused on human behavior in the non-digital world. Watching somebody pick up a fish knife and imitating them to make sure you do it correctly? That's a meme.

But Dawkins also picked out a few things about memes that explain why some can be more successful than others. According to him, the three things that lie behind rapid-spreading memes are longevity (its ability to survive), fecundity (its potential to be copied), and copy fidelity (the ability of the copies to be accurate).

And the internet produces all of these things in spades. A picture of a shiba inu with a stupid expression, which became the hugely popular "doge" meme, can last forever across the internet's huge archives, be copied with a single click, and not lose any of its original color or sharpness no matter how many times it's copied. Memes have been accelerating since the printing press and television were invented, and the internet is basically a perfect breeding environment for them.

The big deal with memes isn't just their existence, though; it's in the sharing. And a lot of the appeal of memes is in tapping into sometimes-obscure cultural references that need a good background knowledge to make any sense at all. Try explaining the two-Kermits meme (in which one Kermit faces off against another in a hood) to anybody who has no idea who Kermit is or hasn't seen the meme before in any form.

That insider knowledge is, according to experts, one of the big things we love about memes: they make us feel part of an elite community, and give us the boost of understanding something slightly odd and non-obvious. One German researcher refers to them as "inside jokes or pieces of hip underground knowledge", and it's that insider status that explains a lot of the appeal.

A large part of the appeal of memes is also the fact that they're not created by one uniform force: they don't all come from the top down. They're not all made by the creators of TV shows, major films or popular singers, for instance, though they can certainly be a source. Rather, memes are generally created by anonymous users (though Snoop Dogg has done his best to make himself into one) who move into the limelight with one creation, and then see it taken, replicated, and altered as it spreads through internet mediums. It's a kind of level playing field, in which everybody can be funny and contribute to the joke. The fact that memes "evolve through remixes and commentary," as one scholar at the University of Warwick noted in 2014, is a key part of their success. They aren't dominated by one particular creator, cost basically nothing to produce at home, and therefore seem more egalitarian.

When it comes to memes in the real world, improvisation is the key to helping them spread. That, at least, is the lesson from an anthropological study in 2014, which looked at how a certain dance move spread through a Zulu tribe and a technique of wrapping ritual arm garments in a synagogue in Jerusalem. Memes, it seems, aren't just about single bits of information (a dance move or an image) that people copy perfectly every time; they spread with people making their own additions and alterations, and those idiosyncratic touches, the researchers found, were "indispensable to the easy transference and preservation" of the meme itself. We love improvising, and internet memes are basically a free-for-all that let us spread our weird wings. They're also, crucially, easy to compare, which means that we're also competing to do the funniest take, the newest usage, or the most on-point application of the meme to some suitable political situation. They feed our human desires for novelty and competition.

Studies of memes increasingly reveal that they take up a big chunk of our time on the internet. Scientists in Indiana launched a tool in 2016 to track memes as they spread and altered online, from Twitter to Tumblr, and found that their journeys were often hugely vast. They also noted that the memes themselves tended to take on social roles in general: "The collective production, consumption and diffusion of information on social media," the lead scientist told the media, "reveals a significant portion of human social life — and is increasingly regarded as a way to 'sense' social trends." Memes, in other words, are now a way in which we pick up on, and comment about, things that concern or interest us. They're part of our digital cultural communication. Memes, as Limor Shifman noted, "diffuse from person to person, but shape and reflect general social mindsets," as people participate, alter, remix and reproduce what matters to them at the current moment. What matters may well be a stupid joke, but hey, that's still important.