It's probably fair to say most of us have seen all the films, and some of us have watched them all multiple times. A number of super-fans can even recite the lines (I'm not one of them, honest).
Harry Potter is without question one of the most popular book-turned-movie series' we've ever seen, with many of the stars going on to become household names.
And while a core group of actors made their names in the business after receiving their big break in the blockbuster wizarding movies, others were already well established by the time they took up their roles.
In addition to the big names who feature heavily throughout the eight movies, there's also a number of super-famous, blink-and-you'll-miss-them, cameos sprinkled in along the way.
And no we're not just talking about Pulp frontman Jarvis Cocker, and those Radiohead members who appeared in the fourth film. This is the One many fans won't be aware of at all.
It turns out The Stone Roses frontman Ian Brown appeared in the third movie, Prisoner of Azkaban. The singer can be seen sitting in The Leaky Cauldron with his head buried in a book – A Brief History of Time by Stephen Hawking.
In one hand he's reading the book and he's using the other to stir his drink without even touching his spoon. You'd have to be Made of Stone not to be impressed.
You can check out his full cameo in the video below.
Talking of his appearance, the musician told The Independent: "I did it for a laugh.
"I've got no ambition to be a movie star. I know the director because my wife's Mexican, and the director's a Mexican called Alfonso Cuaron. Once, at dinner, he said that he had a part for me, so I asked my lads and they said, go for it.
"I think J K Rowling is brilliant - I love the story that she wrote the first book in a café when she was on the dole, and now she's richer than the Queen. As for the tea, I used my magical powers as a bohemian wizard!"
