1. The entire story behind Moony, Wormtail, Padfoot, and Prongs
Otherwise known as Remus Lupin, Peter Pettigrew, Sirius Black, and James Potter. Rowling goes into detail about their antics at Hogwarts during Harry Potter and the Prisoner of Azkaban, which gives more insight into how these characters became friends and why they created the infamous Marauder’s Map. Unfortunately, the movie only gives us minimal background on these complex characters, but we feel the impact of Pettigrew’s betrayal and Sirius’ innocence would have resonated more in the movie with this knowledge.
2. Neville's parents and Gilderoy Lockhart at St. Mungo's
In Harry Potter and the Order of the Phoenix, Arthur Weasley is attacked by Nagini the snake and sent to St. Mungo’s Hospital for Magical Maladies and Injuries. While there, Harry and the Weasley kids run into their old professor, Gilderoy Lockhart, and meet Neville’s parents, who are permanent residents of the hospital after being tortured by Bellatrix Lestrange. This is the first time we actually meet Neville’s parents, which gives us a better look into how Voldemort destroyed their and Neville’s lives and why Neville hates the dark arts so much.
3. The prophecy that Neville could have been The Chosen One.
This one is huge. It was revealed in Harry Potter and the Order of the Phoenix that Neville could have also been The Chosen One. This was one of the biggest themes in the books, but it was completely left out of the movies. If you didn’t read the books, then you have no clue how important it is that Voldemort chose Harry. Voldemort thought Harry was the only child who could be the Chosen One, so he attempted to kill him, thus sealing Harry’s fate. The purpose of there being two potential “Chosen Ones” was to show how Voldemort made rash decisions, which ended up costing him his life in the end. What if he had chosen Neville instead? The story would have been completely different.
4. The background of the horcruxes and Voldemort's family.
In Harry Potter and the Half Blood Prince, Harry and Dumbledore dive into countless memories, trying to piece together Voldemort’s past. We get to see how Voldemort’s witch mother gave a love potion to his muggle father, and being conceived under the effects of a love potion is the reason Voldemort is incapable of love. How could the movies see that as unimportant? Knowing Voldemort’s background helps us understand why he turned into the villain that he did, and while it’s not an excuse for his actions, it’s not his fault that he cannot love.
5. Peeves the Poltergeist
Peeves was infamous for wreaking havoc at Hogwarts, from terrorizing first years to stuffing Mrs. Norris in suits of armor. Even more than that, he provided some much needed comic relief in Harry Potter and the Order of the Phoenix when Umbridge took over the school and imposed all of those ridiculous rules on students. Peeves made it his mission to make her life difficult, which showed that no matter how much he teased and taunted the students, he was on the right side all along.
6. Filch the Squib
If you only went by the movies, you would just think that Argus Filch was a bitter old castle caretaker who only cared about Mrs. Norris. But, if you read Harry Potter and the Chamber of Secrets, you would know that Filch was a Squib. A Squib is a non-magical person born to magical parents and is considered a disgrace to magical society. Filch suffered a hard life and was constantly trying to learn magic, but it was nearly impossible for him. Knowing this, we can see why he was so bitter about being cooped up in a castle full of students who were able to learn magic.
7. "Weasley is Our King"
Malfoy (who else?) and Pansy Parkinson composed this song about Ron and his skills as Gryffindor’s Quidditch keeper in Harry Potter and the Order of the Phoenix. Ron was a good keeper, but he was easily flustered, and the Slytherins took full advantage of that by singing this song during Quidditch games to make sure Ron wouldn’t play well. Ron had a really tough fifth year, and this whole Quidditch segment highlighted his struggles and jealousy towards his best friend’s seemingly effortless successes. The song ended up being a positive thing after Ron won the House Cup for Gryffindor, and they started literally singing his praises.
8. Sir Nicholas' Death Day Party
Nearly Headless Nick (or Sir Nicholas), the Gryffindor ghost, took a liking to Harry, so he proceeded to invite him to his 500th Deathday Party in Harry Potter and the Sorcerer’s Stone. Deathday parties are like gloomy birthday parties, but for the dead. Right off the bat, Harry, Ron, and Hermione get an in-depth look into the “lives” of the ghosts that reside in the castle and their weird habits, like keeping old, moldy food around in an attempt to “taste” it. Sir Nicholas was touched by the student’s attendance, and it helped create a bond between them and the ghost for the remainder of their time at Hogwarts.
9. The supportive messages at Godric's Hollow.
When Harry and Hermione went back to visit Godric’s Hollow in Harry Potter and the Deathly Hallows, they walked up to the Potter’s destroyed and magically masked home to see a multitude of supportive messages and words of encouragement on the gate in front of the house that were written after the first time Voldemort tried to kill Harry. It is one of the most touching parts of the whole book because at this point, Harry and Hermione don’t have much hope left, but seeing the support of so many others reminds them of why they’re searching for the horcruxes in the first place.
10. The messy background of the Dumbledores
While Harry, Ron, and Hermione were in school and before, Dumbledore was regarded as one of the kindest, most trustworthy wizards in all the world, but we learn in Harry Potter and the Deathly Hallows that he had a difficult family life and wasn't always so kind. His sister, Ariana, was bullied by muggle children for practicing magic, which resulted in an unfortunate domino effect for the Dumbledore family. His father went to prison for seeking revenge on the children who harmed his daughter, Ariana was no longer able to control her magic, their mother died during one of Ariana’s fits, he dabbled in the Dark Arts as a teen, and either Dumbledore or his then-friend Grindelwald accidently killed Ariana during a duel.
He didn’t have the best childhood and adolescence, but ultimately those life events made him a better person. Knowing his history helps us realize the magnitude of his transformation and how difficult it must have been for him to become the Headmaster we knew and loved.
(Image via Seth Cooper)