I'm not gonna do the SPOILERS thing anymore, because I'm pretty sure you guys get that already. :)
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16. Harry's and JKR's birthday are on the same day - 31st July
17. The watch that Molly had given to Harry on his 17th birthday belonged to her deceased brother, Fabian Prewett.
18. People think that Ron was Hermione's first boyfriend. Does Viktor Krum ring a bell?
19. During the Second Wizarding War - The Battle of Hogwarts - the Slytherins did not stay (no offence to any Slytherins out there!), some Ravenclaws decided to stay, some decided not to, and all the Gryffindors and Hufflepuffs stayed to fight (in fact, no offence to any house).
20. Moony is Remus. He is a werewolf.
Wormtail is Peter. He is a rat.
Padfoot is Sirius. He is a great black dog which resembles the Grim.
Prongs is James. He is a stag.
They are the Marauders - and no, Snape was NOT included -__-