Watching the 1985 movie Young Sherlock Holmes, it's obvious how much J.K. Rowling swiped to create Harry Potter and the Hogwarts universe. Watson is a bespectacled doofus who looks like Harry Potter. She swapped his role for the lanky redhead, Sherlock Holmes. And she kept the girl in the movie who looks like Hermione as Hermione.
Want more? There's a punk kid with platinum blonde hair, and there's a guy named Dudley in the British boarding school Sherlock, Watson and the Hermione girl romp around solving mysteries in.
This explains why the Young Sherlock Holmes screenwriter, Chris Columbus, took out his vengeance on Rowling by ruining her books in movie form, with those two terrible adaptations he made. It's not, after all, that Columbus lost his drive after he made it big so he ended up turning into a tepid hack of a filmmaker by the point it came time to make the Potter films. He was just pissed that Rowling stole all his ideas so he thought he'd serve revenge just the way the Klingons like it -- cold.