Yes however I was not referring to memes in the broadest sense but memes as humorous (usually) images with captions, shared online. Unlike propaganda and advertising these are spontaneously created by unpaid individuals (though Omar is right there is a certain amount of overlap as always with general categories).
What puts them 'on the side of reality' is that humour, rather like beauty, has deep connections with truth. It doesn't work otherwise. It's one of the ways we update our model of reality...
I’d not say spontaneously, since they evolve over hundreds or thousands of years, but yes, the best memes are evolved to a very high degree of fitness and symbiotic utility. It’s hard to match that on a one-off engineering basis, especially when the desired effect is typically an externality.
What puts them 'on the side of reality' is that humour, rather like beauty, has deep connections with truth. It doesn't work otherwise. It's one of the ways we update our model of reality...