Just last evening, I was watching Food Factory, and they talked about “Cavendish bananas,” which I had never heard of before.
Just now, I was watching Who Wants to be a Millionaire?, and the answer to a question about “the Cavendish variety of these” was “Bananas”!
Pretty amazing, innit? 
Hey, I think Hermitian is looking for you over here: Your Most Recent Experience with the Baader-Meinhof Phenomenon. - In My Humble Opinion - Straight Dope Message Board
I saw that Cavendish question and I didn’t know the answer, but at least I* knew *I didn’t know the answer (important on Millionaire)!
What do you know? That’s the second time I’ve seen a link to that thread this morning. Amazing!
I never knew there was a name for this phenomenon; thanks!
Whenever this happens, I remember the episode of ***That Girl ***where Don is talking to Jerry after buying Ann an engagement ring:
*“You know how you go through life without ever hearing a word, and once you hear it you start hearing it all the time?”
“Baguettes, right?”
“Baguettes!”*
I thought it was just from Repo Man: