Albus Dumbledore is considered the wisest character in the Harry Potter series. The Headmaster of Hogwarts certainly backed up this claim by offering advice to the protagonist and being able to foresee the outcome of events based on his deductive reasoning.
However, Dumbledore was also wrong at times, both with how he assumed things would go and for certain decisions he made. All things considered, the impact of his positive and negative outlooks were felt to such degrees that it might just be split between the two. With that in mind, it’s worth taking a deeper analysis of the areas where Dumbledore was concerned.
Wrong: That Muggles Deserve To Be Subjugated
The difference in ideologies wasn’t what led to the separation of Dumbledore and Grindelwald, as the two had originally shared the same vision. The young Albus considered enslaving the Muggle population as he thought it was his right as a wizard to rule over them.
By his own admission, the older Albus admitted he was a fool to ever think this way as they were the makings of a tyrant. Still, there’s no escaping the fact that he thought that Muggles deserved to be subjugated and be at the mercy of wizards.
Right: Voldemort Using Harry's Blood Would Be His Doom
Voldemort devised the plan to get Harry to him in order to extract his blood to create a new body. While this did work, Voldemort inadvertently extended the magical protection of Lily’s sacrifice by sharing Harry’s blood.
This ended up being one of the greatest mistakes in the series as Voldemort ensured his enemy couldn’t die by his hand. Dumbledore had come to this conclusion in Goblet of Fire itself, as Harry had noted there had been a gleam of triumph in Dumbledore’s eyes when he learned of this. He had deduced that Harry could now survive his fated death, which was exactly how it panned out.
Wrong: That Grindelwald Had Genuine Love For Him
Albus’s motives to find the Deathly Hallows had romantic links attached to them, as he had been in love with Grindelwald and thought of their partnership as a mixture of personal and professional. He was very wrong to consider this way seeing as Grindelwald wasn’t genuine with his feelings.
Instead, he ended up betraying Albus by attacking Aberforth and causing the death of Ariana. Albus had thought their love would have prevailed over any issues Grindelwald had with his family but this thought was sadly misplaced.
Right: That Voldemort Had Multiple Horcruxes
The idea that there could be more than one Horcrux was inconceivable to wizards, but Voldemort had indeed gone further by creating as many as seven of these. Dumbledore had not only concluded that Voldemort had Horcruxes but that there were multiple of them.
He had carried this notion for years and needed Professor Slughorn’s memory of discussing Horcruxes to be certain of it. Dumbledore was also right on the money over the identity of these Horcruxes as each of them was the one he had deduced them to be.
Wrong: To Openly Favor Gryffindor For The House Cup
There were more than a few times that Gryffindor deserved to win the House cup but Dumbledore deliberately letting them win wasn’t the right thing to do. That’s because it caused a contempt for him amongst the Slytherins who didn’t bother to have any loyalty toward him.
It also furthered the notion that Harry was Dumbledore’s favorite, which the likes of Voldemort and Cornelius Fudge looked to exploit. Not to mention how it also divided the rest of the Houses, meaning Dumbledore created a bigger rift within the students.
Right: His Absolute Faith In Snape
More than a few characters tried to convince Dumbledore that his trust in Snape was misplaced but the Headmaster wouldn’t hear of it. When it appeared as if Snape had killed him, it seemed to be Dumbledore’s greatest mistake to have Snape by his side.
Of course, the truth was that Snape was his most valuable ally as Dumbledore shared most of his secrets with him. Snape was also the reason that he survived the effects of the curse on Marvolo Gaunt’s ring, along with being the one who carried on the tasks to ensure that Harry defeated Voldemort.
Wrong: That The Elder Wand's Power Would Die With Him
One of the things Dumbledore had planned for his demise was the end of the Elder wand’s power since Snape didn’t technically beat him. However, Dumbledore was wrong to assume that he wouldn’t be beaten at all as Malfoy disarmed him at the Astronomy tower.
This made Malfoy the owner of the Elder wand, thus foiling Dumbledore’s plan and continuing the wand’s lineage. Dumbledore hadn’t been foolish in his assumption that the wand’s power would die out, but he was wrong in his belief that he would go undefeated.
Right: That He Wasn't To Be Trusted With Power
Dumbledore claimed that he had learned from the mistakes of his youth that he wasn’t meant to be the owner of the Deathly Hallows. He believed he had the tendency to go mad with power and it was the reason why he refused to become the Minister of Magic. He was right to think this way as well, seeing as even Dumbledore’s well-meant plans were ethically inappropriate.
Among these were his willingness to sacrifice Harry, force Sirius into house arrest, place very dangerous creatures and situations at Hogwarts, and be all-around open to breaking ethical boundaries if it helped his means. For this reason, Dumbledore was correct in acknowledging his weakness in positions of power.
Wrong: Making Snape Teach Harry Occlumency
The entire Occlumency angle isn’t one that fans particularly enjoyed since it amounted to nothing and Snape made things worse for Harry when the latter didn’t learn how to close his mind to Voldemort. Dumbledore had hoped Snape would overlook his issues with James but this didn’t turn out to be the case.
Instead, Snape took the Occlumency lessons as a way to antagonize Harry further, who started to think of the idea as a joke. Dumbledore should have taught Harry Occlumency himself for him to understand its importance, as the ordeal with Snape had the worst consequences.
Right: That Ron Would Want To Return To Harry
Due to the corruption from the locket Horcrux, Ron became estranged from Harry before having a huge fight that resulted in him abandoning both his best friend and Hermione. He then had a change of heart and was guided by Dumbledore’s deluminator to his friends’ location weeks later.
While Ron figured Dumbledore left him the deluminator because he knew he would take off, Harry was right in his claim that Dumbledore actually understood that Ron would want to come back. As evidenced by Ron’s role in saving Harry’s life from the Horcrux, Dumbledore certainly knew what he was doing.