A collection of Harry Potter books. (Sarah L. Voisin/The Washington Post)

This is part of an occasional series in which we explain what’s behind a popular meme. We like to call it memesplaining; you might call it meme-ruining. Regardless, if you just chanced upon a joke, tweet, image, app or GIF you don’t understand, we have the answers — insofar as answers can be had.

After reading a book on space as a teen, I learned that some scientists believe that the universe is expanding so much that, one day, it might collapse on us. The thought used to give me nightmares. I googled this for about 40 minutes today and learned that the current scientific literature is way more complicated than my early-2000s science book for teens. Plus, everyone knows that the sun is going to torch the Earth way before the universe ends.

Anyway, welcome to my article about a Harry Potter meme, one that burns the creator of the wildly popular franchise for refusing to stop expanding the Hogwarts universe.

The meme: J.K. Rowling can’t move on

The meme format is simple: You create a fictional scenario in which J.K. Rowling, the author of the Harry Potter series, keeps adding new factoids about the Wizarding World into the official canon of Harry Potter, unprompted.

There are a lot of other popular ones that I can’t include here because of their graphic sexual content.

Why is this meme happening?

When the last Harry Potter book came out, most passionate fans thought they’d spend years grappling with what to do with themselves without new Potter stories to look forward to. The opposite turned out to be true. Instead, Rowling wouldn’t stop adding to her universe, confronting some fans with a different challenge. On message boards and videos, in fan art and fan fiction, they had taken the world she had created and made it their own. As the author revealed new details about her characters, they had to reconcile Rowling’s vision with their imaginations.

I wrote about all this in 2016 after Rowling launched Pottermore, a membership-based website that functioned like an official encyclopedia of the Hogwarts universe. On that site, and in tweets, Rowling informed her fans of essential facts: Ron Weasley’s “patronus” is a Jack Russell terrier, Moaning Myrtle’s full name is Myrtle Elizabeth Warren, and Harry Potter’s uncle loves “Top Gear.”

At the time, fans were grappling with the release of “The Cursed Child,” a Rowling-endorsed play set when the original trio of the books were all grown up. They celebrated some details, like the casting of a black actress as Hermione, but the play got a mixed reception. One disappointed fan, who had spent years reading fan fiction about adult Harry and the gang, told me that reading the script “felt like I was reading a worse version of things I’d seen done for years."

Some fans felt uneasy about Rowling’s additions because they felt like retroactive attempts to make her original books more diverse. Several told me that the creators of Harry Potter fan fiction had already picked up the slack, and Rowling was late to the party.

In a video that went viral in October, popular YouTuber Gus Johnson captured the frustration some fans felt watching Rowling tinker with her characters: “It seems like you’re changing them after the fact so that you could seem more inclusive and get good press.”

And then there was the tweet from Pottermore about how wizards pooped their robes.

Not long after that, the Internet’s patience with Rowling’s constantly expanding Harry Potter universe collapsed, giving us the meme.

What does Rowling think about the meme?

Rowling hasn’t responded to the meme specifically, but she has, to some degree, addressed the criticisms beneath it.

The topic came up most recently in the lead-up to “Fantastic Beasts: The Crimes of Grindelwald,” a prequel to the Harry Potter series. The film reveals that Nagini, a snake who was perpetually by Voldemort’s side in the original series, was actually once a human woman. In the film, South Korean actress Claudia Kim plays the human Nagini.

The revelation that the villain’s subservient pet was actually a cursed Asian woman didn’t sit well with parts of the Potter fan base. When one fan tweeted at Rowling, accusing her of trying to score “woke points” with the casting choice, Rowling responded by talking about the origins of the name “Nagini.”