Harry Potter is such an immense fantasy series that it got fans talking, speculating and dreaming like no fandom before. Internet forums were abuzz with excited chatter and wild theories, some of which Potter fans were determined were true.
Then Book 7 came along and crushed many of these theories into the dust. Looking back, it's just awesome how much people cared, and how thoughtful and knowledgeable the fans had to be to come up with ideas like these.
Check out 7 of the best Harry Potter theories that were GOLD - until Book 7 smashed them to smithereens...
1. Harry Potter was the Heir of Gryffindor
The Theory: The Potters are direct descendants of Godric Gryffindor. The battle of Harry vs. Voldemort is an age-old repetition of the epic battle between Godric Gryffindor and Salazar Slytherin.
Why it could have worked: There's a nice symmetry to the idea - Voldemort is the descendant of Slytherin so why can't Harry be related to Gryffindor? The intonations of Harry drawing the sword from the hat (as opposed to King Arthur's sword from a stone) also point towards a more mythical, time-old root to Harry's struggle with Voldemort.
2. Harry and Hermione were siblings
The theory: The Potters had a baby girl before Harry was born - this was Hermione.
Why it could have worked: The Potters hid their daughter, Hermione, with a muggle family to protect her from the Death Eaters. This explains Hermione's fiercely protective feelings towards Harry, her lack of romantic interest despite their strong bond, and the lack of information we're given about the Grangers. You can read a full explanation of this theory here.
3. Lily and James saw grown-up Harry before they died
The Theory: Harry used the Time Turner to visit his parents in Godric's Hollow before they died.
Why it could have worked: Harry could have shown his parents that he'd grow up into a decent person, letting them die happier and making their sacrifice easier, in just the same way that seeing his future self allows Harry to cast an amazing Patronus.
This would also add weight to Snape's hatred of Harry - if he'd seen grown-up Harry visit his parents and seemingly give his blessing to his parents' death - despite the fact that it was always inevitable, as J.K.R. is very clear about events in time being immovable - he would always hold Harry directly responsible for Lily dying.
The nice thing about this theory is that it could still be true - maybe Harry ends up doing this at some point during his career as an Auror...
4. Neville's Candy Wrappers
The Theory: Neville's mom has been secretly communicating with him through messages written on old candy wrappers.
Why it could have worked: Neville tells Harry that his catatonic mom, who he visited at St. Mungo's, gave him old gum wrappers and he kept all of them. We were waiting to find out the significance of these covert communications - vital knowledge from a damaged but valuable Auror? - but this never materialized.
5. The Department of Mysteries Holds the Key
The Theory: The locked door at the Department of Mysteries was gonna be the crux of the entire series.
Why it could have worked: Dumbledore's explanation of the room seems too ominous for it to NOT reappear! I mean, "a force... more wonderful and more terrible than death"? Come on!
There is a room in the Department of Mysteries that is kept locked at all times. It contains a force that is at once more wonderful and more terrible than death, than human intelligence, than the forces of nature. It is also, perhaps, the most mysterious of the many subjects for study that reside there. It is the power held within that room that you possess in such quantities and which Voldemort has not at all.
6. Ron and Dumbledore are the same person
The Theory: Ron Weasley and Albus Dumbledore are the same person - Ron traveled back in time to protect Harry.
Why it could have worked: Ron and Dumbledore both have reddish hair, long noses and a massive scar on the left knee... maybe Dumbledore got that scar when Ron's leg was broken? If anyone would sacrifice their current life to help Harry in the past, it's Dumbledore. But then all that actual, verified Dumbledore back story came along and smashed the Ronbledore idea to bits.
7. Harry Potter is not the real chosen one
The Theory: The prophecy confirmed that the one who could vanquish Voldemort was born in July to parents who'd thrice defied him. Potter fans know that this could have referred to Harry Potter OR Neville Longbottom.
Why it could have worked: Dumbledore tells Harry that it's him who's the chosen one - but what if he lied? Maybe it was all a ruse - drawing attention away from Neville so that he'd stay safe to eventually kill Voldemort? Think about it - it totally works... except that J.K. Rowling probably would have mentioned it if it was the massive twist to Book 7!
You can read a fuller explanation of this theory here.