Why is this suddenly everywhere?

I first learned about buzkashi in a book about mountain climbing. Fast-forward a week or so, when I’m reading a totally unrelated magazine article about Afghanistan, and there it was again: "buzkashi. " What are the odds that I would encounter another mention of this obscure thing so soon after learning about it? You’ve probably experienced this same thing – not with buzkashi, of course, but with some other obscure term or concept that you've never heard before and then suddenly you notice it popping up all over the place in a way that feels almost spooky. This feeling is common enough that it has a name: the Frequency Illusion. Think about all the noise you’re exposed to at any given time; your brain is constantly flagging important information out of that, and filtering out the rest. When it comes to new information, your brain basically has to guess whether something is potentially important or not, based on all sorts of clues; and stuff that it guesses might be worth holding onto, get filed into your memory. It’ll often take us a while to stumble back across that same information. But every so often, it pops up again in quick succession. And – since patterns can be important, I mean, heck, our brains probably evolved to notice patterns to help us avoid the poison berries or whatever – our pattern-seeking brains take notice; and think: this thing must be everywhere! But most of the time, especially in our modern, noise-packed lives, this second exposure is just a coincidence.