Filch is the cantankerous caretaker of Hogwarts School of Witchcraft and Wizardry. He is the creator of the best cat name of all time. He also happens to be a Squib ― a non-magical individual who is born to a magical parent.
As caretaker, Filch is tasked with overseeing the cleanliness and general upkeep of Hogwarts. This job involves patrolling the corridors at night, giving students detention and maintaining the overall hygiene of the school. And as a Squib, Filch has to do that job ... without magic.
Let's go over that again. Filch has to keep an entire freaking castle clean without using magic to do it.
How is it that one of, if not the only non-magical individual on Hogwarts' grounds gets stuck with the most physically demanding job? A job that any number of students or staff could do with just the flick of their wands?
It turns out we are not the first Harry Potter readers to consider this conundrum. As one Redditor put it, "Isn't it cruel to have Filch as a janitor when he can't clean with magic?"
Nevertheless, there does appear to be a method to J.K. Rowling's madness.
Remember how Hermione campaigns to free Hogwarts' brigade of house-elves in Harry Potter and the Goblet of Fire? These house-elves toil away in the kitchens, move students' bags and clean the dormitories using their own special kind of magic. Surely Filch must have a managerial role over these house-elves, who can use their magic to keep Hogwarts clean.
That system makes sense, in theory. But in practice, we know that Filch gets stuck doing a lot of grunt work without magic.
In Harry Potter and the Chamber of Secrets, Ron Weasley serves detention with Filch after using his father's flying car to get to school. As punishment, Ron and Filch must polish Hogwarts' silver without magic. Later in the book, Filch spends all night mopping up in the bathroom when Moaning Myrtle floods her toilet. In Harry Potter and the Order of the Phoenix, Filch must ferry students across Fred and George Weasley's portable swamp until Professor Flitwick removes most of it. And in the final "Harry Potter" film, we see Filch begin to sweep up the rubble after the Battle of Hogwarts.
Can someone cut this guy a break?
Listen, we get that Filch is a rather unpleasant fellow. But if you had this Sisyphean task on your hands, we doubt you'd be all sunshine, daisies and butter mellow.
No wonder the man went berserk and murdered everyone at the Red Wedding.
(Yes, we know this is the wrong reference ... but it's so wrong, it might just be right.)