Just a meme I've seen floating around on Tumblr and reddit where people will respond to a question with information about a word that sounds similar to the one in the original question. The next person in the chain responds with "no, you're thinking of" and then responds the same way.
Here's an example.
There's also a subreddit dedicated to this phenomenon but it's not very active.
https://www.reddit.com/r/NYTO