Anakin Skywalker ultimately ended up hating Obi-Wan Kenobi for many misguided reasons, but Darth Vader's subconscious response to the Jedi's final declaration of love in the Star Wars prequels shows the real reason he could never forgive him.
In Episode III, just before they are to set off on their respective missions, Obi-Wan and Anakin share a farewell. Anakin admits to Obi-Wan that he has been arrogant and unappreciative of his training, and apologizes to his master.
He slays Sidious and returns to Obi-Wan, begging for atonement by execution, only to be met with true forgiveness instead.
Obi-Wan seems to have reconciled with Anakin as he appeared beside his old friend as a spirit while they watched Anakin's children celebrate their victory against the Empire together.
He does. Right at the end. With Luke crying over him and Vader sensing his anguish and pain he had inflicted on all those who had cared for him.
Giving in to his feelings, Anakin cuts off Mace Windu's hand, giving Palpatine the opportunity to kill him. Anakin regrets this almost instantly, but the thought of Padme was stronger than his remorse This is the moment Anakin officially became Darth Vader and led to serious issues in the Skywalker Saga.
He couldn't bring himself to kill Darth Vader, however, because he continues to associate him with the Anakin he trained as a boy. This is also the exact reason why Obi-Wan didn't kill Anakin on Mustafar despite the opportunity a decade earlier in Star Wars: Episode III - Revenge of the Sith.
Yes. In the book 'Tatooine Ghost', Leia learns of Anakin's life prior to his evolution into the Darth Vader personae. This revelation leads her to forgive him. She even named her third child in memory of her father.
David Porter provides some great philosophical context to why Obi-Wan would not regret leaving Anakin alive, as it was obviously “the will of the Force” that Obi-Wan be unable to finish him off, and “the will of the Force” that Anakin live on to kill Sidious himself in the future.
Darth Vader hated Obi-Wan Kenobi because he hated himself. This started when he thought that Kenobi was the one that poisoned Padmé into turning against Anakin when he turned to the dark side. But the truth was that Anakin was merely projecting his own self-hatred toward Obi-Wan.
Update: So apparently Hayden Christensen said in the Q&A yesterday in Toronto that there will always be a little bit of Anakin in Vader, and that line was Anakin trying to absolve Obi-Wan of guilt.
But Obi-Wan Kenobi's finale helped make Ben's case. After defeating Darth Vader in the Obi-Wan Kenobi finale, Obi-Wan broke down and began tearing up when he saw Anakin's scars. It was the first time he had seen Anakin's face since leaving him to burn on Mustafar, and so he apologized for everything that had happened.
But, on top of all of that, the biggest reason Obi-Wan doesn't know Anakin is alive is that the last time he saw Anakin Skywalker in Revenge of the Sith, Ben literally left him for dead. Ten years later, in Episode 2 of Obi-Wan Kenobi, he learns Anakin is alive. This is the first time it happens.
He explained to Luke, “I took it upon myself to train him as a Jedi. I thought I could instruct him just as well as Yoda. I was wrong.” His guilt was apparent in Revenge of the Sith, when he explicitly told Anakin in the heat of their duel on Mustafar, “I have failed you, Anakin.
He had a softish spot for a handful of individuals and unlike many other Sith, Vader didn't generally kill innocent people for no reason - but he always hated the Jedi and he had no regrets about what happened to them. The best proof of this is how he throws himself into becoming the Empire's primary Jedi hunter.
It's not shown, but it is clearly insinuated that Anakin killed the younglings. This is confirmed later in the movie when Obi-Wan informs Padme that Anakin killed them. Both are torn apart with hurt and confusion, trying to make sense of something so terrible. How could Anakin do such a thing?
Yes, his entire character since then was a self loathing tragic monster who has little reason to care about anything. Betraying Mace Windu instantly made him regret his act of impulse, Padme's death and rejection of his actions later on made it stick. To Anakin, he tried to rationalize he had no choice.
Padme did not cheat on Anakin here is why: Padmé and a Anakins relationship was very strong they both were deeply in love. In the clone wars there is an episode called ““The Rise of Clovis.” long story short a former flame of Padmé's returns and is trying to rekindle with Padmé. Unbeknownst to him she is married.
Obi-Wan knew Anakin through and through and understood his overconfidence and arrogance. He knew Anakin would fight with rage and aggression, while he remained cool and calculated. Pairing his understanding of Anakin with his knowledge of Soresu ultimately gave him the upper hand in the battle.
It's the kind of extra and flamboyant gesture that the Jedi seemed to love, but perhaps Obi-Wan felt that this grand gesture of sacrificing himself to the Force would give Luke (and Leia, and Han) the push needed to take his training seriously, and show him just how powerful a Jedi could become.
In a recent interview with The Wrap, Harold noted that the decision to have Obi-Wan believe that he'd killed Anakin on Mustafar, only to learn the truth years after the fact, came from a place of finding the story as it was being told.
The maverick Jedi Master Qui-Gon Jinn comes before the Jedi High Council, which Windu is a member of, and offers to train Anakin Skywalker, believing that the boy is the Chosen One of Jedi prophecy. Windu and the other Council members decline, deeming Anakin too old and full of fear.
Despite his somewhat pure origins as a Jedi, Darth Vader definitely has plenty of moments where he genuinely enjoys what he does on the dark side.
Darth Vader did not 'forget' he was Anakin. He believed he was not Anakin Skywalker; a completely different person whom he killed. You will read in EU materials, that he referred to his memories as Anakin, as 'The Jedi'. He suppressed most of Anakin Skywalker's memories - his memories while he was Anakin.