They both blow out candles on July 31 . And that’s not the only influence Rowling had on her characters: She’s said that Hermione is a bit like her when she was younger, and her favorite animal is an otter—which is, of course, Hermione’s Patronus. Plus, both Dumbledore and Rowling like sherbert lemons (Rowling said that the wizard’s “got good taste”).

2. THE DEMENTORS ARE BASED ON ROWLING’S STRUGGLE WITH DEPRESSION AFTER HER MOTHER’S DEATH. 

Rowling’s mother, who had multiple sclerosis, died in 1990, after which Rowling suffered a period of depression. She would use the experience to characterize the Harry Potter’s dementors, creepy creatures that feed on human emotion. “It's so difficult to describe depression to someone who's never been there because it's not sadness," Rowley told Oprah Winfrey. “I know sadness. Sadness is to cry and to feel. But it's that cold absence of feeling—that really hollowed-out feeling. That's what Dementors are.”

3. She seriously considered killing off Ron "out of sheer spite" about halfway through the series, but ultimately decided that she couldn't do it to the character.