There aren’t many joys in life that can compare to a tasty Harry Potter theory, which is why I was so excited when my colleague (and fellow Potter nerd) Hemal Jhaveri told me there was a new one floating around about Hermione Granger’s cat, Crookshanks. I popped out of my chair, got myself a fresh cup of coffee and was supremely disappointed when I came back to read it. Here’s why:

Theory: Hermione Granger’s cat, Crookshanks, used to be owned by Lily Potter

The theory, which you can read here if you want, posits that Crookshanks found itself in the hands of the Magical Menagerie following Voldemort’s murder of Lily Potter and remained there until Hermione purchased it 10 years later.

The first problem with this is that it makes the same mistake most Harry Potter animal theories make: It assumes all the animals we meet throughout the series have to be connected in some way despite minimal evidence they actually are. Is Snape a werewolf? Is Draco Malfoy a werewolf? Does the snake Harry Potter frees in book one become Nagini? All these theories fall into the same trap.

The Potter universe is a big place, and each animal can exist independently from one another, the same way that my pet cat can exist in the same world as your pet cat without us having to manufacture some connection between them. The only connection our pet cats have is that they’re both cats that live on planet earth.

The other big problem with this theory is that it depends on a key piece of evidence that is actually proof of the contrary.

The theory states that Crookshanks recognized Peter Pettigrew — James Potter’s former friend who betrayed him to Lord Voldemort — when he was hiding as Ron Weasley’s rat, Scabbers. According to the theory, the only way Crookshanks could have known this is if Crookshanks knew Peter Pettigrew from his time as Lily’s pet, when Pettigrew, James Potter and Sirius Black would all spend time together.

But that’s not true.

We know that Crookshanks, described as “either a very big cat or quite a small tiger,” looks that way because he is a half-cat, half-kneazle mix. A kneazle, by the way, is a cat-like magical creature that is larger than a regular cat, has bigger ears, a different tale, and whose core trait is its ability to sense untrustworthy characters. A muggle would be alarmed by the sight of a kneazle, so aside from the fact that it would be unusual for a muggle-born witch like Lily Potter to risk outing herself with a half-kneazle as a pet, Crookshanks’ skepticism of Scabbers is simply proof of something we already knew.

In conclusion, not a great theory. Not even a good one. Come on Potter nerds, we’re better than this.