A meme is an idea, behavior, or style that spreads from person to person within a culture.
Imagine the radioactive hazard symbol. The fact that you are imagining a yellow circle with a black center circle and three trapezoidal shapes at even intervals is a testament not only to the visibility of the ionizing radiation symbol but also to the definition of a meme. A symbol is a meme. It can communicate a vast array of ideas with its seemingly simple imagery. A word is similar to a symbol. A symbol is composed of lines and shapes and sometimes colors in order to communicate a complex concept within a small space, a word is composed of lines shaped into various letters when arranged in the correct combination communicates a concept. Words need to be known before they can be read, as is the case with symbols, but what if simply seeing a symbol instantly communicated what it was?
This is the terror meme. It paralyzes it's victims with fear and uncertainty. It is not magical, it is not a curse, it's a meme.
Of course, there are other memes. There is the one that tells your brain you need to run as fast as you can and if you slow down for any reason you're going to die, you better keep moving whatever the cost. There's the one that tells your brain if you take one more step then your heart will stop. The one that tells your brain if you urinate again your soul will slip out of you leaving your body an empty husk. The one that tells your brain if you dance you'll live forever, and can actually spread to anybody who approaches you and tries to make you stop dancing, and soon whole villages are dancing. There's one that tells your brain you need to share it with everybody you meet and you do this by talking about the weather, and soon everybody is talking about the weather, what it's like right now and what it will be like tomorrow and what it was like last year and how that's different from now. Sometimes, instead, you share the meme by talking about what a meme is.
Perhaps you've encountered one of these memes, perhaps you will encounter a new one soon. Flabonic.