Harry Potter fans are a legion. J.K. Rowling's books and the subsequent movies that followed shaped up most of our childhood. But there's the thing about a universe that arrives in the form of books and then goes on to become a series of movies- it has a legion of divided fans.
Let me make something perfectly clear. We, the book readers consider ourselves better than those who have just watched the movies. Mostly because we are. The movie watchers can lay their claim on the fandom as much as they want but they will never know what we have experienced.
1. Gryffindors make a parody of a Slytherin song after Ron wins them the Quidditch match.
If you haven't read the books, you have no idea about an entire song dedicated to the genius of Ronald Weasley in Quidditch. The song was literally carved out of a mock song the Slytherins used to sing to throw Ron of his game during his early days the Gryffindor Keeper. It was Ron's moment of glory. He wasn't the Chosen One like Harry or a genius like Hermione but he was bloody good at the sport and had girls swooning over him.
2. The Marauders: Unregistered animagi who transformed to accompany Remus during full moons.
Sure, in the Order of Phoenix, we get a glimpse of the Marauders taking Snape for a ride but that was it. It's actually sad that movie watchers do not know that not just Sirius but all four of them were animagi. James was a stag, while Peter Pettigrew was a rat. And all of them had not registered with the Ministry. And they did this just so that they could stay with Remus Lupin in the Shrieking Shack on the night of the full moon when he turned into a werewolf.
3. The History of the Whomping Willow
In the Chamber of Secrets, Harry and Ron's flying Ford gets hit by the Willow in the school grounds. Snape wanted to expel them for they had injured a tree that had been planted before their births. Well, the tree was planted when Remus Lupin joined Hogwarts. Dumbledore was sympathetic to the boy and had hence, had the tree planted there so that Remus could use it to make his way to the Shrieking Shack when he transformed into a werewolf.
4. The Veelas: Part-human part-humanoids that could capture men's imaginations.
In the Goblet of Fire, we see Fleur Delacour and others veelas from Beauxbatons make their way into the Hogwarts dining hall and make everyone swoon over them. They are semi-human and semi- humanoids. Although the movie does show their captivating power over men, there is no mention of Veelas.
5. Hermione started S.P.E.W for the upliftment of house-elves.
The Society for the Promotion of Elfish Welfare. Yup. Hermione started S.P.E.W after she read about and understood the thousands of years of oppression and slavery house-elves had been going through. And BTW, the delicious food you see at the Hogwarts feast doesn't cook itself. There are house elves working their ass off so they could feed hungry ass fucks like Ron.
6. Dumbledore writes a letter to Petunia Evans rejecting her request to be admitted into Hogwarts.
Petunia Evans might have called Lily a freak and but deep down she was just a jealous sister who wanted to be a wizard. So she wrote a letter to Albus Dumbledore requesting him to accept her into Hogwarts, which he respectfully and kindly rejected in another letter.
7. Dumbledore again writes to Petunia asking her to take a baby Harry Potter into her house.
Following the death of James and Lily Potter and the demise of Lord Voldemort, a lot of wizarding families would have been proud to have adopted Harry. But Dumbledore knew that the Dark Lord would one day return in search of the boy. He had also understood the ancient magic Lily had conjured by sacrificing herself to save Harry. And the same blood ran in Petunia's veins. So as long as Harry was with her and called 4 Privet Drive Little Whinging his home, he could not be hurt by the Dark Lord or his allies. Dumbledore explained this in a letter to Petunia and she obliged by taking him in.
8. Marietta Edgecombe ratted out Dumbledore's Army, not Cho Chang.
It wasn't Cho Chang who ratted Harry and the Dumbledore's Army to Umbridge. It was her best friend Marietta Edgecombe. The movie simply focusses on Harry and Cho's brief relationship without even discussing the fallout.
9. The support messages at Godric's Hollow outside the Potters' old house.
Harry and Hermione visit Godric's Hollow in the 7th book to find clues about the next horcrux and how to destroy Salazar Slytherin's locket. When they reach there, they find the old abandoned and ruined house where James and Lily Potter were killed. A statue had been erected in the village to commemorate the terrible incidents that had happened. When they reached the old house, they saw messages people had left for the Potters. While it might not have been important to the storyline, it gave Harry much needed hope and support he needed to survive the ordeal.
10. Albus Dumbledore's relationship with Grindelwald & the death of Ariana Dumbledore.
Grindelwald appears only briefly in the movies and they never explored the dark past of the great Albus Dumbledore, his relationship with Grindelwald and the death of his sister or how Dumbledore came in possession of the Elder Wand.
11. Dudley's change of heart when he realises Harry was being hunted down by Voldemort.
When Harry finally left his aunt and uncle's house, they also had to move out for security purposes. Dudley, in his final moments of farewell, told Harry that he wasn't a mere waste of space. And it finally dawned on Harry that Dudley had been doing his best to be thankful to Harry all summer. Dudley then goes on to thank Harry for saving his life.
12. Dobby stole Gillyweed from Snape's office.
Neville might have handed over the Gillyweed to Harry during the second task of the Triwizard tournament but it was Dobby who stole it from Snape's office using elfish magic.
13. Barty Crouch Jr.'s escape from Azkaban & the dementor's kiss that destroyed his soul.
We know that Crouch Jr. had impersonated Mad-Eye Moody throughout the 4th year. But only book readers will know the story of his escape from Azkaban and then from his father's imperious curse & Winky's binding charm. It will also be unknown to the movie watchers that Crouch Jr. was subjected to a dementor's kiss before he could testify to the return of Lord Voldemort.
14. Harry's actual intention for smuggling himself into Hogwarts was not to start a rebellion.
Unlike in the movies, Harry did not actually come back to Hogwarts to fight off Snape. His only intention was to steal Rowena Ravenclaw's diadem and destroy it. But while he was hiding in the Ravenclaw common room, he sees Amycus Carrow spitting on McGonagall's face making him lose his shit and using the cruciatus curse on him and starting the rebellion.
15. Voldemort died a mortal death and did not scatter into the air like butterflies.
Unlike in the movies, Voldemort did not turn into a thousand ugly butterflies, nor did his body become fragments. He fell down lifeless like a mortal.
There are many more such instances from the books that people who have only watched the movies will never know. So do us all a favour and before you go on raising banners under the name, 'Potterhead', read the freaking books.