The Baader-Meinhof pheonomenon is kind of like Deja Vu in the sense that it’s something weird that many people have unexpectedly and can’t readily explain.
From the Damn Interesting Article:
Baader-Meinhof is the phenomenon where one happens upon some obscure piece of information– often an unfamiliar word or name– and soon afterwards encounters the same subject again, often repeatedly. Anytime the phrase “That’s so weird, I just heard about that the other day” would be appropriate, the utterer is hip-deep in Baader-Meinhof.
I would simplify the explanation to the following: the Baader-Meinhof phenomenon takes place when something that actually pops up around you fairly often, but which you ignore, is brought to your attention.
At that point you actually notice it happening because it has a signature in your brain due to recent exposure and/or interaction. So it’s not that it necessarily starts happening more (although that could be the case if it’s a meme that’s propagating), but more likely just a sensitivity increase in the perceiver of the stimulus.
Another good example of this is learning about a particular vehicle on a car lot and then noticing a million of them around town. Although, that could admittedly be caused by the meme phenomenon as well.
