Rowling's mother Anne died after suffering from multiple sclerosis. Rowling was writing Harry Potter at the time and had never shared the story with her mother. Anne's death heavily affected Rowling's writing and she introduced much more detail about Harry's loss in the first book because she knew how it felt.
Steven Spielberg was initially chosen to direct the film, planning to create an animated film with American actor Haley-Joel Osment to provide Harry's voice. Spielberg declined the offer after choosing to direct A.I.: Artificial Intelligence
The children would film for four hours and then do schoolwork for three hours
Daniel Radcliffe was initially meant to wear green eye contacts as his eyes are blue, however the lenses gave Radcliffe extreme irritation and after consulting with Rowling it was agreed that Harry's eyes could be blue
Rowling progressed from living on state benefits to multi-millionaire within five years. She is also the best-selling living author in the U.K.
Anticipating that the target audience of young boys might not want to read a book written by a woman, Rowling's publishers asked that she use two initials, rather than her full name.
Rowling's parents met on a train from King's Cross Station
Differences between book and film:
some added dialogue, which Rowling approved of. Rowling made sure things wouldn't directly contradict with events in future novels
Minor characters removal: Professor Binns, History of Magic teacher and Peeves the poltergeist
The film begins different from the book, starting with Dumbledore, Professor McGonagall, and Hagrid, leaving Harry with the Dursleys.
Harry's unpleasant days spent at Mrs. Figgs
The scene at the zoo changed the boa constrictor (from the book) into a Burmese Python
Harry and Draco's encounter at Madam Malkin's robe shop is only in the book, not the film
In the film, Norbert is taken away by Dumbledore when in the book, Harry and Hermione deliver him to Charlie Weasley's friends
Because of the above change, the reason for the detention in the Forbidden Forest is changed: Harry, Ron and Hermione receive detention because they are caught at Hagrid's after hours by Malfoy, who also receives detention for being out of bed after hours
The Quidditch pitch is altered to be an open field circled by the spectator towers