Why did Dumbledore said after all this time?

Lily has been dead for 15 years, so Dumbledore says “after all this time” (meaning Severus still loves Lily after 15 year?) With a look of anguish on his face, Severus replies “Always”, meaning he has loved her always. He loved her as a child, a school boy, and still now, even after her death.

Why was Dumbledore surprised by Snape Patronus?

In order to show Dumbledore that he’s still not over Lily and that he still cares for everything she would,Snape casts patronus charm. Watching the doe emerge out of Snape’s wand assures Dumbledore that Snape cared for Harry as much as he did for Lily.

Why is Dumbledore surprised that Snape is still acting like this?

Dumbledore seems genuinely surprised that Snape is still acting out of his love for Lily. He is confident that telling Snape that Harry must die won’t cause him disquiet. He questions why Snape’s motivations would be unchanged “after all this time”. [Snape] stood up.

Why didn’t Draco kill Snape?

Also, once Draco had been tasked with killing him, and Snape had taken the Unbreakable Vow (more or less on Dumbledore’s instructions) he didn’t want Draco to be corrupted by killing him – especially as that would mean Draco got the mastery of the wand – and he didn’t want Snape to die of *not* killing him.

How did Dumbledore get the silver doe out of the office?

“ 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.

Why is Snape’s Patronus a doe?

Lily’s patronus was a doe – either coincidentally or specifically because of James’ Animagus form (probably the latter). You can’t choose your Patronus. The fact that Snape’s is a doe – is Lily – means that he still truly loves her, and that his feelings for her haven’t weakened over the years.