Harry Potter shares a birthday with JK Rowling, the series' author. When you're an author, you can pop in whatever details you like into your books, and JK did just that. She also made sure that Hermione shared some of her characteristics when she was the same age.

JK Rowling scribbled the names of the Hogwarts houses while she was on a flight. She grabbed the first thing she saw that she could write on ... an air sickness bag. How's that for spur of the moment?

JK Rowling knew how the books would end before she even wrote all of them. This is not entirely unusual, though. Many successful authors have entire stories fleshed out in their heads before they start writing.

JK Rowling has struggled with depression, and for her, the dementors signify the sad feelings that are common with depression. Watch how Harry Potter characters describe dementors - as if they feel sad and empty when the dementors are around.

Harry Potter and the Sorcer's Stone was almost called Harry Potter and the School of Magic. Of course, in the UK, the title is Harry Potter and the Philosopher's Stone.

Originally, Arthur Weasley was slated to die at the fangs of Nagini. But, because there are so few positive dad role models in the story of Harry, Rowling decided to let him live. Whew!

Brad Pitt would have been a bit too old to play Harry, so this one is a no brainer. And, as much as we like Haley Joel and Jonathan, Daniel Radcliffe IS Harry Potter.

Harry Potter's eyes are green. Daniel Radcliffe's eyes are blue. The movies reconciled these differences by making Lily's eyes blue in the movies, too.

Mere wooden brooms would have broken during the scenes. To make sure that the actors were safe, the brooms in the movies were made out of titanium.

Although some actors go deep into their characters for a movie, Daniel Radcliffe did not allow Harry's scar to be tattooed onto his face. The movie makeup artists did get a lot of experience reapplying it over and over, though.

Helena Bonham Carter is considered a rather odd bird to begin with, and she's known for really connecting with her characters. She is said to have kept Bellatrix Lestrange's teeth. Now, that's a nice memento.

Michael Jackson wanted to head up a Harry Potter musical, according to JK Rowling. Most offers of these types of productions, she has turned down.

Stephen King is said to have been particularly enamored with the character of Dolores Umbridge. We think she would have made a great character in one of his books.

Arthur Weasley's flying car was a Ford Anglia. The Anglia was a Ford sold in the UK from 1939 to 1967.

The Harry Potter chapter, "The Boy Who Lived," is known as "The Laddie Wha Lived," in Ireland. And, that's not even the strangest translation of Harry Potter books. They are all mostly tailored to their audience.

Viktor Krum attended Durmstrang Institute. Durmstrang is the wizarding school that is located somewhere in the Netherlands.

Actually, the books don't address what happened to Dolores Umbridge. But JK Rowling clarified the matter in an interview - Umbridge was sent to Azkaban.

The cat who played Mrs. McGonagall in Harry Potter was named Mrs. P. Head. We're not sure if any of the other animagus actors had names.

Professor Snape was in love with Lily Potter. Everyone knows that! If you didn't, go back and reread the books.

No, we're not making this one up. The word "dumbledore" really does mean "bumblebee" in Old English. Look it up.

Yup, it's true. As Rowling was writing the books, she found herself in a stressful life situation. Many authors take stress out on their characters. Thankfully, Rowling restrained herself, and Ron got to live to wizard another day.

Hogwarts is hidden from the prying eyes of wayward muggles. If muggles accidentally came across Hogwarts, all they would see is an old, falling down building and a "keep out" sign.

Professor Snape did not die laughing. Sirius Black and Fred Weasley did, and JK Rowling did this intentionally as both were portrayed as tricksters.

Hermione's patronus is an otter. Fun fact ... Ron's patronus is a Jack Russell terrier.

Tom Felton makes a great Draco Malfoy, but he would have made a hideous Hermione. Tom Felton did, however, audition for the parts of Harry and Ron.

Fred and George Weasley were born on April 1st, which is April Fools Day. That JK Rowling is a real wit!

Fred and George were inadvertently hitting Voldemort's face, since he was wrapped in Quirrell's turban. Bet you never thought of that, did you?

Remus Lupin's patronus was a wolf, not a werewolf as some people believe. Remus hated all things werewolf.

McGonagall's husband was the victim of a venomous Tentacula bite. Fun fact ... when she was young, McGonagall was in love with a muggle.

The last sentence of the Harry Potter book series is "All was well." JK Rowling was actually going to make the last word "scar," but she changed her mind.

Ginny Weasley became a professional Quidditch player after her time at Hogwarts. However, when she and Harry had children, Ginny retired from sports and devoted herself to raising their children.

Harry and Ginny named their first born after Harry's dad, James. His middle name was Sirius, after Sirius Black, Harry's godfather.

Ron became an Auror after he left Hogwarts. A fitting occupation, we think, since Ron would be hard pressed to write or teach.

Draco Malfoy almost did not attend Hogwarts. Draco almost went to Durmstrang Institute, the school that Viktor Krum attended.

Harry's owl was named Hedwig. We thought we'd end on an easier note, since this was a pretty tough quiz. Also, we miss Hedwig and wanted to make sure she was mentioned.