1. Harry actually returned the Elder Wand to Professor Dumbledore's grave at the end of Deathly Hallows.
2. Voldemort's mother gave his father a love potion, which is why they ended up together and how Voldemort was conceived. This is the main reason Voldemort could never love anything.
3. Hermione founded S.P.E.W. (the Society for the Promotion of Elfish Welfare), which fought for the equality of house-elves in the wizarding world.
4. During the Battle of Hogwarts, Professor Trelawney catapulted crystal balls at Death Eaters to defend herself.
5. Professor McGonagall also transformed desks to stampede toward the Death Eaters. She used this transformation spell most notably in Sorcerer's Stone when she turned desks into pigs.
6. Marietta Edgecombe was the one who snitched on Dumbledore's Army to Professor Umbridge and Filch, not Cho Chang.
7. In Sorcerer's Stone, Fred and George enchanted snowballs and repeatedly hit Professor Quirrell in the back of his head with them, which means they were hitting Voldemort directly in the face.
8. During the visit to Godric's Hollow, Harry put his hand on the gate outside of his parents' cottage and a sign appeared from the ground, covered in messages in support of Harry.
9. Petunia actually wrote Dumbledore a letter when she was a kid because she so desperately wanted to attend Hogwarts.
10. In Order of the Phoenix, Hermione and Ron were appointed as Gryffindor Prefects.
11. Just before Dumbledore was killed by Snape, he immobilized Harry and threw the Invisibility Cloak on him.
12. Teddy Lupin — Lupin and Tonks's son — was raised by his grandmother Andromeda Tonks. He eventually befriended Harry and went to his house a few times a week for dinner.
13. After Amycus Carrow spat on McGonagall, Harry used the Cruciatus Curse on him.
14. In Deathly Hallows, Fred, George, Lupin, and others ran a secret radio station that could only be heard if you knew the password. This way, everyone could communicate safely with one another.
15. Rita Skeeter was an Animagus. She transformed into a beetle and sneaked around to collect information for her articles, which is why they were always so "juicy."
16. Dudley and Harry actually had a heart-to-heart in Deathly Hallows, and Dudley thanked him for saving his life.
17. The Ministry of Magic could never tell who was casting spells in heavily populated wizarding residencies. That was why young witches and wizards were able to use magic during the holiday break away from Hogwarts.
18. And Neville Longbottom was born a few hours before Harry, making them the two infants in the prophecy against Voldemort. Neville could've been the Chosen One, but Voldemort chose to target Harry instead.
What do *you* think is a fascinating fact from the Harry Potter books that more people should know about? Let us know in the comments below!
Note: Some submissions have been edited for length and/or clarity.