1) An inscription on the Mirror of Erised reads "I show not your face but your heart'a desire.
2) Expecto Patronum literally translates to "I await a guardian" in Latin.
3) Rowling said if Voldemort saw a boggart it would take the shape of his won corpse, since death was his greatest fear.
4) Originally Rowling wanted to kill off Arthur Weasley in the fifth book, but then she switched him for Sirius Black.
5) Dementors are a physical representation of Rowling's experience with depression.
6) Voldemort is incapable of love because he was conceived under a love potion.
7) Snape hated Neville because Neville was nearly the Chosen One. If he had been chosen, lily wouldn't have died so young.
8) Dementors don't breed; they grow like fungus where there is decay.
9) The day harry and ron saved hermione from the troll - the day they became friends - was the 10 year anniversary of Harry's parent's death.
10) Bellatrix means "female warrior" in Latin.
11) Rowling said she seriously considered killing off Ron in the middle of the series.
12) In the Harry Potter universe, there are an estimated 3000 wizards living in Great Britain.
13) Voldemort was 71 years old when he died.