"The  truth...is a beautiful and terrible thing, and should therefore be treated with great caution."
     -- Albus Dumbledore

Essay:Why did Harry do that?

Mysteries:
Here's a nice list of the more puzzling mysteries and inconsistencies found in the Harry Potter books. The online fan community has debated each of these topics in endless detail and some explanations have been offered. Care to suggest your own solutions to these knotty questions? Head for Harry Potter for GrownUps or go to the Lexicon's own forum and join the discussion! Please don't email me your theories. It's not that I'm anti-social or stuck up or think that I have all the answers. It's just that I receive over a hundred emails per day and I just can't get into discussions about things like this. I don't have time. 

For more information about this topic, see the Notes About This Page.
 

• Who is Mrs. Figg?
• This mystery was solved in GF and in interviews.
• Who are Harry's family?
• Where did Snape go at the end of GF?
• Why did Lupin transform into a werewolf only when the full moon came out from behind the clouds? Don't werewolves automatically change shape at the full moon, whether or not there are clouds? And how long does it take to drink a potion? How could he have been so incredibly stupid as to forget to take it that night?
• JKR's partial answer: "The moon wasn't up when he entered the Shrieking Shack." (Sch2) This really doesn't answer the question, however. Of course, lycanthropy might easily work a little differently in the Potter universe. It is even possible that there are more than one type of werewolf, one that is mostly human and another that is mostly wolf. This is supported by the fact that we've heard that werewolves live in the Forest, which seems unlikely when they're normal humans most of the time.
• What did the centaurs mean by "Mars is bright tonight"?
• Mars is the god of war, which suggests that the Centaurs saw conflict coming. This was undoubtedly true, since Voldemort was wandering their forest and they were familiar with Harry Potter. I'm not sure that it would take a lot of divination ability to figure this out. 
• Fans have looked into the actual position of Mars on the night Harry was in the Forest (May 26, 1992, after 11 pm). Mars actually wasn't visible in the sky over Scotland until about 3 am, having risen around 2 am, but then it was easily the brightest object in its part of the sky. Mars wasn't in a particularly bright part of its cycle, however, being at magnitude 1.18. Since Rowling makes no effort to match her fictional world to real world dates, this is probably a moot point. But it's interesting nevertheless.
• Do the Hogwarts toilets really empty into the lake? Don't the merpeople object?
• How did the Chamber of Secrets' entrance, constructed almost a thousand years ago, get hidden inside modern plumbing?
• The most reasonable explanation for this phenomenon is that Hogwarts castle adjusts over the years to changes in technology and architecture. After all, castles of the large stone variety weren't being built anywhere in Britain a thousand years ago, meaning that  Hogwarts probably started life looking quite a bit different than it looks now. So the Chamber, in the tradition of the staircases which lead somewhere different on different days and the disappearing chamber pot room, probably adjusted its entrance to fit the form of the magical castle to which it connects. 
• Does Neville ever learn to ride a broom? What does Madame Hooch do with all her spare time when that one First Year flying lesson of the year is done?
• What's up with that "gleam of triumph" in Dumbledore's eye when he heard that Voldemort had used Harry's blood in his rebirthing ceremony? Does that mean Dumbledore is really evil?
• It is extremely doubtful that Dumbledore is secretly evil. Here's a great explanation of that infamous "gleam" from Kevin in the Lexicon Forum:
The full context in which Harry sees the "gleam of something like triumph in Dumbledore's eyes" is that Voldemort now has Harry's blood in him. Voldemort has a habit of forgetting details which can be his downfall. On pages 652-653 of Goblet of Fire Voldemort says: "His mother left upon him traces of her sacrifice... This is old magic, I should have remembered it." In Chamber of secrets Tom Riddle forgets that phoenix tears can heal. I think that Dumbledore's gleam of triumph is that he has realized that Voldemort has once more done something which is going to bring about his downfall. Just what, I am not sure. Perhaps now he has enough human in him to die. Perhaps having Harry's blood in him will cause the Avada Kedavra curse to rebound on to Voldemort if it actual hits Harry. Remember that professor Binns has said that Dumbledore could do the dark arts. I suspect that Dumbledore is better versed in the dark arts than Voldemort is. He simply chooses not to use them. Dumbledore says that it is our choices that are important. 
• When did Arthur and Molly Weasley attend Hogwarts?
• Who's going to end up in love with whom?
• Why did just having that Tournament mean no one got to play Quidditch for an entire year?
• Speaking of the Triwizard Tournament, why was everyone so excited to go watch the second and third tasks? Why were there even stands set up? They couldn't see what was going on under that Lake (we know this since Mercus has to explain to Dumbledore what transpired), nor could they see into the maze, or Moody wouldn't have been able to manipulate events without everyone knowing. So what did the crowd do the whole time? And for this they gave up Quidditch?
• In which years is all this happening?
• Socks and wristwatches...
• Why did Fred and George never notice Peter Pettigrew on the Marauder's Map when he was disguised as Scabbers?
• Speaking of the Marauder's Map, how can it show all the rooms and passages in that three-dimensional castle on a two-dimensional piece of parchment?
• If Flamel's age is given as being "665 last year" in an old book, doesn't that mean that he is really much older than that now? Assuming the book was a hundred years old, Flamel would be 766 now, not 666, right?
• Assuming that the Nicolas Flamel of the Harry Potter universe is in any way similar to the Flamel of the real world, there is no conceivable way to rectify the dates of his birth and the age given in the old book Hermione discovers. However, there is a perfectly reasonable explanation for this discrepency. It is clear that the pictures in books are not the only things that move and change. The text must update itself as well, so as the years go by the age given by the book would change accordingly. 
• Are all the Slytherins nasty and ugly? Do they all turn into Dark Wizards? Then what happens if you're sorted into Slytherin but you're NOT evil? Are you just out of luck?
• What's the story of the Bloody Baron and why is he able to control Peeves?
• It says that "There wasn't a witch or wizard who went bad who wasn't from Slytherin." So that must mean that Peter Pettigrew was in Slytherin, right?
• No. It is true that Hagrid does say this, but Hagrid is not stating a fact, he's exaggerating because of his dislike for Slytherin house. Certainly many of the evil wizards and witches did come from Slytherin, a house whose philosophy seems to embrace the Dark Arts and evil more than any other. And we know that Snape, while a student at Hogwarts, hung around with a group that all became Death Eaters. But it isn't logical for the story for all the evil folks to come from one house. After all, Sirius is still assumed to be evil by most in the Wizarding World, but he's almost certainly from Gryffindor.
• What was Professor Trelawney's FIRST correct prediction?
• Why did Voldemort consider it so important to kill Harry? And why did he seem reluctant to kill Lily?
• How did Sirius order that Firebolt without giving himself away? How did he get the money out of his vault? And for that matter, how did Mrs. Weasley get money out of Harry's vault?
• How did Crouch Jr. learn all that powerful magic when he went to Azkaban as a very young man and spent the years after he escaped under the Imperius Curse? Yet he could fool the Goblet of Fire and out-duel Mad-Eye Moody?
• And since we're on the subject of "not enough time," when did Crouch Jr. or Voldemort find time to create Polyjuice Potion to allow Crouch to impersonate Moody? It takes months to prepare the ingredients and brew that potion, according to CS. 
• Where do the female prefects bathe? And does the mermaid on the wall watch people as they take baths?
• What happened between Snape and Dumbledore that makes Albus trust him so much? What is his second chance? What happened to the first?
• What happened on November 1, 1981, to keep Harry and Hagrid busy until evening? Where were they? Where did Hagrid see McGonangall to tell her that Dumbledore would turn up on Privet Drive?
• We see from Harry's boggart that turned into a dementor that boggarts inherit the characteristics and magical powers of the form it takes or imitates (the dementor made the room icy cold...). So when Lupin faced it and it changed into a moon, why didn't he automatically change into a werewolf?
• Why change the Triwizard Cup into a Portkey? Wouldn't it have been easier for Moody to just change something else--a book, for example--and get Harry to touch it at some point? Why all the elaborate charade with entering Harry into the Triwizard Tournament, helping him to win, etc.?
• In SS16, it says that Fluffy wakes up when the music stops, and falls asleep only when music is played. Did Fluffy stay up all of the five months that nobody went into third corridor? Was an ancient magic invoked so that Fluffy could stay awake for so long?
• If Voldemort considered it so important to kill Harry, why did he offer to have Harry to join him in SS17?
• When Mrs. Weasley went into her vault at Gringotts, there was only one galleon and a few sickles. By looking at the back of Quidditch through the Ages or Fantastic Beasts and Where to Find Them, we see that something that costs 14 sickles and 3 knuts equals 4 dollars. Ok, so at that rate, the entire Weasleys'  fortune would be a grand total of around 10 dollars. They can't afford books for Fred, George, Ron, Ginny, and Percy with that! Heck, they can't even afford three books total!

Notes on this page
There are really two types of puzzles in the Harry Potter books. One type is the unanswered questions which are probably plot points to be answered later in the series. These types of mysteries engender all kinds of speculation and discussion, but will not be answered until the rest of the books are published.

The other type of puzzle is the inconsistency, the (usually) minor error in continuity which is almost unavoidable in a complex and detailed series of books such as this. Inconsistencies, unlike unanswered questions, will probably not be solved by future books. They're just mistakes, and that's the way it is. Some of these happen in an earlier book because when she wrote it, Rowling hadn't invented some detail which appears in a later book. An excellent example is Apparition, which doesn't appear until book two. In book one, Dumbledore flies to London, apparently on a broomstick, which seems silly when he could certainly have Apparated instead. Other such errors come from the fact that some element of a book, such as the Marauder's Map, has powers which Rowling probably didn't conisder. The question of why Peter didn't show up on the map when Fred and George had it falls into that category. 

It is a long-standing and honored tradition among fans of books, movies, and television shows to invent plausible explanations for these errors. Folks have been doing this for Star Trek since the early days of fandom, back in the 1970s. These explanations are not canon, of course. But working this sort of thing out is a work of fan fiction which attempts to validate the series a little more. It's a form of respect and affection for the material, and is not meant to criticize or demean the original at all. If it bothers you to see this kind of nit-picking, by all means browse on to another page of the Lexicon. But if you're like most fans, you'll find the explanations and speculations about the mysteries and puzzles of the Harry Potter series to be delightful reading.