In the material around the film from the Legends timeline, it's established that by the end of Star Wars: Episode III - Revenge of the Sith,
When Luke (Mark Hamill) is attacked, though, Obi-Wan saves him and reveals his true identity. In the film, Obi-Wan and Darth Vader face off once more and it is clear that Obi-Wan knows it is Anakin he is dualling. Hence, somewhere within his 20-years of self-exile Obi-Wan learned that Anakin was alive.
The answer could be that Obi-Wan's exile, both physical and spiritual, on Tatooine prevented news from reaching him. On a practical level, Obi-Wan did not know that Anakin had survived simply because he was isolated on Tatooine.
Darth Vader's true identity was a closely guarded secret, and only a handful of people knew he was really Anakin Skywalker. Jedi Master Anakin Skywalker was a celebrated hero of the Clone Wars, and the galaxy believed he was killed during Order 66, along with the rest of the Jedi.
Only a Master of Evil
The last time Obi-Wan saw Anakin Skywalker was the fateful duel in which he chopped his apprentice into bits and left him melting on the side of a volcano.
Anakin admits to Obi-Wan that he has been arrogant and unappreciative of his training, and apologizes to his master. Obi-Wan assures Anakin that he is proud of him, telling him that he has become a "far greater Jedi than I could ever hope to be."
Because what's being conveyed is that Obi-Wan Kenobi is accepting that Anakin Skywalker is “dead” and a Sith Lord named Darth Vader is in his former friend's place. He's washing his hands of his responsibility to his former apprentice by acknowledging that Anakin is, in his mind, a lost cause.
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.
The Chosen One was revealed to be Anakin Skywalker, who conceived by the Force itself via the mystical one-celled organisms called midi-chlorians completely without outside influence.
Reva knows that Anakin Skywalker is Darth Vader because she was one of his targets—a child—during the Order 66 killings that took place during the events of Star Wars Episode III: Revenge of the Sith.
Despite seeing Vader as an idol, Kylo conveniently ignored his grandfather's redemption. He was well aware of what happened, and it's likely Luke himself who told Ben about the events of Star Wars: Return of the Jedi.
because his Padawan Ahsoka. never became a knight. She left the order when she was still a padawan. This is why Anakin was denied the rank of master.
Well, yes, but no. Kylo Ren saw himself as carrying on the tradition embodied by his grandfather and personal hero, Darth Vader, although his understanding of Anakin Skywalker's history was twisted by Snoke.
Darth Vader hates Obi-Wan, not because he blames him for his fall to the Dark Side, but because he turned Padmé against him and destroyed his body.
It's hard to say for certain - but even if Vader was aware of Yoda's existence, chances are he probably did not know where Yoda was; being the Jedi Master that he was, he had an exceptionally strong connection to the force - and so, he could have easily hidden his location and energy in the force whilst on Dagobah, all ...
For years, Vader hated Obi-Wan, having been struck down by his mentor and left for dead while also believing the Jedi had worked to turn his true love Padmé against him.
The Jedi from the Star Wars prequels, including Master Yoda, did not understand Anakin Skywalker's Chosen One prophecy for these essential reasons. The Jedi of the Star Wars prequel era clearly did not understand the famous Chosen One prophecy.
In Star Wars' original trilogy, it is revealed that Anakin Skywalker's son, Luke Skywalker, is the the true Chosen One of the galaxy.
Anakin does not have even the slightest bit of remorse. By the end, he feels nothing but anger. Although he feels regret for killing Padme, he still helps the evil Emperor. The film ends with Anakins standing side by side with the man on whose behalf he has committed all his crimes.
The story is Anakin was manipulated to the dark side by Palpatine based on fears of losing Padme and appeals to his desire power and agency, over his life and the galaxy as a whole.
“The tear [on Anakin's face] says that he knows what he's done, but he has now committed himself to a path that he may not agree with… but he is going to go on anyway. It's the one moment that says he's self-aware that he's rationalizing all his behavior.
He slays Sidious and returns to Obi-Wan, begging for atonement by execution, only to be met with true forgiveness instead. But just as this fantasy Obi-Wan refuses to strike his former friend down, Vader refuses to turn his back on the dark.
His suffering meant he always expected the worst in people, but because of this, it caused his biggest flaw. This mentality stretched back to when Anakin was a Padawan, as seen in Part V of Obi-Wan Kenobi. As Anakin and his master train at the Jedi Temple, he's able to overwhelm Kenobi and disarm him.
The only reason we may consider Obi-Wan saving Anakin after their battle is because we know that there is still good inside Vader, and that we was never totally lost. It's just that, from Obi-Wan perspective and experience with Anakin that day, there was no possibility of that.