Quote 1
"I resented it, Harry."
Dumbledore stated it baldly, coldly. He was now looking over the top of Harry's head, into the distance.
"I was gifted, I was brilliant. I wanted escape. I wanted to shine. I wanted glory.
"Do not misunderstand me," he said, and pain crossed the face so that he looked ancient again. "I loved them. I loved my parents, I loved my brother and my sister, but I was selfish, Harry, more selfish than you, who are a remarkably selfless person, could possibly imagine." (35.57-60)
Dumbledore, it seems, wasn't quite strong enough to sacrifice his future for his family, as he was asked to do – one of the reasons why he recognizes Harry as a better man. Harry's selflessness is remarkable; his choice to sacrifice himself is something that most of us wouldn't have been able to do!
Quote 2
"Your point about Wizard dominance being FOR THE MUGGLES' OWN GOOD – this, I think is the crucial point… We seize control FOR THE GREATER GOOD." (18.34)
Whoa, there – this quote from a teenage Dumbledore to teenage Grindelwald is shocking. However, it raises an intriguing question – what is "the greater good"? How, for that matter, do we determine what is good or evil? Why should the two former friends have split, but continued, each in his own way, to hold to similar ideals, but on different sides?
Quote 3
"Master of death, Harry, Master of Death! Was I better, ultimately, than Voldemort?"
"Of course you were," said Harry. "Of course – how can you ask that? You never killed if you could avoid it!"
"True, true," said Dumbledore, and he was like a child seeking reassurance. "Yet I to sought a way to conquer death, Harry."
"Not the way he did," said Harry. […] "Hallows, not Horcruxes." (29)
Again, the question of ends vs. means arises – if Dumbledore and Voldemort had the same goal in mind, does it even matter that they worked towards it in different ways? Harry reassures Dumbledore that it does… what do you think?
Quote 4
"You are the true master of death, because the true master does not seek to run away from Death. He accepts that he must die, and understands that there are far, far worse things in the living world than dying." (35.88)
Dumbledore explains the real meaning of "master of death" here – it doesn't mean that Harry commands Death, but rather that he's kind of on equal terms with it. Like the third brother in the story (his ancestor), he's willing to approach Death face-to-face when the time is right, and thus has a greater understanding of it… or, rather, has come to an understanding with it.
Quote 5
"But this is touching, Severus," said Dumbledore seriously. "Have you grown to care for the boy, after all?"
"For him?" shouted Snape. "Expecto Patronum!"
From the tip of his wand burst the silver doe: She landed on the office floor, bounded once across the office, and soared out of the window. Dumbledore watched her fly away, and as her silvery glow faded he turned back to Snape, and his eyes were full of tears.
"After all this time?"
"Always," said Snape. (33)
Snape's finest quality – his loyal love for Lily – informs the most intimate part of himself, his Patronus.
Quote 6
"Yes, we have been given power and yes, that power gives us the right to rule, but it also gives us responsibilities over the ruled. We must stress this point, it will be the foundation stone upon which we build… where we meet resistance, we must use only the force that is necessary and no more." (18.34)
This quote, from a letter that young Dumbledore wrote to Grindelwald, demonstrates the dangers of having too much power – the idea that the added strength of magic makes wizards fit to rule (albeit "responsibly") over Muggles is the overly enthusiastic and dangerously idealistic claim of an immature, young wizard.
Quote 7
"Can you forgive me?" he said. "Can you forgive me for not trusting you? For not telling you? Harry, I only feared that you would fail as I had failed. I only dreaded that you would make my mistakes. I crave your pardon, Harry. I have known, for some time now, that you are the better man." (35.45)
Dumbledore feels terrible for not telling Harry about the Hallows and for not being honest with him – and perhaps it was egotistical of him to assume that Harry would make all the same mistakes he did. However, now that Dumbledore has realized that he was wrong, he's learned from his mistake.
Quote 8
"And his knowledge remained woefully incomplete, Harry! That which Voldemort does not value, he takes no trouble to comprehend. Of house-elves and children's tales, of love, loyalty, and innocence, Voldemort knows and understands nothing. Nothing." (35.26)
Again, the difference between Harry's understanding of the world and Voldemort's is made clear – Voldemort is completely consumed by his lust for power, and his ignorance of the things that actually make life good and worthwhile are what really demonstrate his true evil.
Quote 9
"Do not pity the dead, Harry. Pity the living, and, above all, those who live without love. By returning, you may ensure that fewer souls are maimed, fewer families are torn apart. If that seems to you a worthy goal, then we say good-bye for the present."
Harry nodded and sighed. Leaving this place would not be nearly as hard as walking into the forest had been, but it was warm and light and peaceful here, and he knew that he was heading back to pain and fear of more loss. (35.94-95)
Yet again, Harry chooses to plow ahead and do the right thing – but it's hard. He's been walking down a long, dark road in this novel, and when he thought he got to the end of it, it still wasn't actually the end… but he'll keep walking, anyway.
Quote 10
"That which Voldemort does not value, he takes no trouble to comprehend. Of house-elves and children's tales, of love, loyalty, and innocence, Voldemort knows and understands nothing. Nothing. That they all have a power beyond his own, a power beyond the reach of any magic is a truth he has never grasped." (35.28)
Ah… so, real power, it seems, springs from love, something Dumbledore has said all along, but that Voldemort has never listened to. And this is why Harry triumphs over the Dark Lord in the end; he recognizes, unlike his foe, that he isn't alone in the world and wouldn't want to be, and that it's love that makes the world go 'round.
Quote 11
"Maybe a man in a million could unite the Hallows, Harry. I was fit only to possess the meanest of them, the least extraordinary. I was fit to own the Elder Wand, and not to boast of it, and not to kill with it. I was permitted to tame and to use it, because I took it, not for gain, but to save others from it.
"But the Cloak, I took out of vain curiosity, and so it could never have worked for me as it works for you, its true owner. The stone I would have used in an attempt to drag back those who are at peace, rather than to enable my self-sacrifice, as you did. You are the worthy possessor of the Hallows." (35.84-85)
Dumbledore recognizes wisely that power works best for those who deserve it – he could never have controlled all three Hallows because he never merited them. This is something that Voldemort, who thinks he can seize whatever power he wants, will never understand.