All the movies:
- Magically gifted children age at an extremely inconsistent rate. (They aged 6 magic years in 10 human years).
- All the students immediately outgrew their wizarding robes after the second year, the robes will rarely be seen again.
- Harry Potter is the only one who gets into trouble for using magic outside of Hogwarts.
- 16-year-old Voldemort looks nothing like 17-year-old Voldemort (or 11-year-old Voldemort for that matter). If George Lucas had been involved this would have been fixed by the third release of the DVDs.
- Most of Gryffindor (a house based on bravery) is comprised of students too afraid of their own shadows to be of much use half of the time.
- The “good enough” mentality is just as strong in the magical community.
Harry Potter and the Sorcerer’s Stone:
- The Sorting is not conducted in alphabetical order — what kind of system is that? Oh, and you’ll never see another Sorting.
- It is okay for teachers to play favorites, particularly Heads of Households.
Harry Potter and the Chamber of Secrets:
- Children get injured constantly at Hogwarts and no one raises an eyebrow, but as soon as a few students get temporarily petrified, the future of this 1000-year-old institution is in jeopardy.
- Sometimes the students age in reverse order.
- Hagrid’s home (and really all of Hogwarts) is ridiculously overrun with spiders, at least until it no longer serves as a plot device.
Harry Potter and the Prisoner of Azkaban:
- I don’t know what Dumbledore was doing during Harry’s second summer break, but he must have been hitting the gym or something. He started the third year looking like an entirely new man.
- Malfoy is the only student to get injured for which there appears to be consequences to the staff and other involved parties.
Harry Potter and the Goblet of Fire:
- For some reason everyone decided that 70s long hair was cool. The girls, the guys, everyone.
- Harry only uses magic four times (in a movie about wizards).
Harry Potter and the Order of the Phoenix:
- Despite the looming threat of Voldemort’s return, everyone managed to find a barber shop over the fourth year summer break.
- Harry is a rage-oholic who likes his rage-ohol shouted at, not stirred.
Harry Potter and the Half-blood Prince:
- Harry has apparently become homeless and now lives in a dirty subway tunnel.
- All of Harry Potter’s problems from the previous movie would have been solved if they just looked in his memories.
- The Slug Club sounds even worse when spoken aloud.
- Any fool could look at 11-year-old Voldemort and know he was going to grow up to be a mass murderer.
- They should be brewing gallons of “Liquid Luck.”
Harry Potter and the Deathly Hallows 1 & 2:
- Harry doesn’t like other people taking risks for his sake. He’d rather let Voldemort just win already.
- Despite being free for 5 years, Dobby continues to wear the same tattered rags. His only addition is a pair of shoes. Yeah, that’s all you needed Dobby.
- The Weasley’s rebuilt The Burrow to look exactly like the old one did. That means their shabby house is by choice and not by circumstance.
- Every wizard’s house is apparently located in the middle of some huge empty field (except Snape’s).
- Even though people Disapparate together (holding hands) they rarely Apparate near each other.
- Harry is a wizard who never seems to think of magic as a solution to a problem. He’d rather jump into a freezing pool of ice water than cast a spell to warm the water first.
- Everyone is from Godric’s Hollow (which Harry didn’t know). It is apparently the source of all wizarding families.
- Gringott’s is probably not where you want to bank anymore, because they lost roughly 100% of their staff as a result of Harry’s break-in.
- Based on the number of people who died on that bridge, there can’t be all that many wizards left.
This post made possible by a grant from SciFi.StackExchange. That isn’t just a plug at the end of a PBS show, it’s the truth. Something like a ba-jillion years ago (Nov 15th 2011) I was one of the recipients of the Complete Collection of Harry Potter on DVD. I chose DVD because a) I didn’t have a BluRay, and b) I am not forward looking. I received this grant on the promise to help promote Harry Potter questions and answers on the site. Thanks to my contributions (and maybe others, I’m not keeping track) as of the writing of this post Harry Potter is the #1 tag on SciFi.StackExchange.