It was during his viewing of the hologram that Obi-Wan knew Darth Vader was Anakin. This is because Sidious said, “Henceforth, you shall be known as Darth… Vader”.
Throughout the fight, Obi-Wan knew that killing Anakin would "burn his heart to ash." He also expressed regret at the thought of the man Anakin could have become.
What Obi Wan didn't know is that Anakin survived the aftermath of their vicious battle on Mustafar. Kenobi assumed Anakin perished as a result of that conflict. He wasn't on the planet to witness Palpatine show up to save his apprentice from succumbing to his battle wounds.
Very few people knew that Darth Vader and Anakin Skywalker were the same person up to his death in 5 ABY. Imperials who knew in the current canon: Sidious (emperor), Grand Moff Tarkin, all or most of the Inquisitors, Grand Admiral Thrawn, various clones in the early empire.
And while Lucas' change removes Obi-Wan from blaming himself for training Anakin, it doesn't remove his guilt of how Anakin turned out. In the back of his mind, Obi-Wan is trying to live up to Qui-Gon's expectations; he's trying to train Anakin as Qui-Gon would have.
When Obi-Wan's Force Ghost Talked With Darth Vader After a New Hope - Star Wars Explained
Did Obi-Wan forgive Anakin?
No, but… it's complicated? Thing is, he never really felt like there was anything to forgive Anakin for. But he definitely never forgave Darth Vader. When Anakin fell to the dark side, Obi Wan took it as his own failure.
And while his warnings don't work, at the very least, it shows that Maul became aware of Anakin and what he would soon become. With the rise of the Empire, it's likely Maul caught on to Vader's existence pretty quickly.
R2-D2 was present when Padmé gave birth to Leia and Luke, so he knew Luke was Anakin's son – but what he didn't know was that Anakin became Darth Vader. In addition to that, Anakin's fall was surely a painful event in R2-D2's life, one that he definitely wouldn't like to remember or even talk about.
And all the way up until the third sister told him otherwise, Obi-Wan truly and completely believed that Anakin was dead. He believed that he died on the banks of Mustafar. And even if they knew for a fact the Anakin had survived, it comes back to the split personality.
On a practical level, Obi-Wan did not know that Anakin had survived simply because he was isolated on Tatooine. Although Obi-Wan did not see Anakin die after their battle on Mustafar in Star Wars: Revenge of the Sith, he reasonably could have assumed that Anakin would die from his injuries.
It was during his viewing of the hologram that Obi-Wan knew Darth Vader was Anakin. This is because Sidious said, “Henceforth, you shall be known as Darth… Vader”.
And he's already murdered Mace Windu at Palpatine's behest, more or less by stabbing the Jedi in the back. The canonical comic Star Wars: Darth Vader #7 confirms the younglings' deaths caused Anakin grief, self-loathing, hatred, and pain, fueling his descent even further into the Dark Side.
Though Obi-Wan was often an important ally for Anakin, the young Jedi could never see past his envy, even going far enough to allow himself to believe that his master was having an affair with his wife. In the end, Anakin's own jealousy was his undoing and the reason that he would never surpass his master.
Darth Vader: I am not your failure, Obi-Wan. You didn't kill Anakin Skywalker. I did. ————————————————— Even in the depths of his hatred, Anakin gives his old mentor one last mercy, absolving him of his guilt.
Yoda. Yoda's knowledge of Luke Skywalker's true parentage was also confirmed in Return of the Jedi. As with Obi-Wan, Yoda believed that Anakin's fall to the dark side made him unsalvageable, with the Darth Vader persona being his only identity following his ascension to Sith Lordship.
Instead, the diminutive droid appears to have kept his own counsel, perhaps wary of interfering too much in Luke's personal journey. C-3PO lost those memories, but he remained with Han and Leia's family after Return of the Jedi, so can reasonably be assumed to have learned the truth by eavesdropping.
Leia's Force abilities and her lack of awareness of her true identity also contributed to Vader's inability to sense their familial connection. Vader's denial of Anakin Skywalker's legacy and his fear of getting hurt again prevented him from realizing the truth about his children until later in the original trilogy.
Darth Vader acts like he doesn't even know C-3PO or R2D2. They were with him since he was a child. He did everything he could to forget his past. Also, his plating had been replaced many times, and protocol droids all look very similar.
Darth Vader didn't learn he had a daughter until Return of the Jedi, when he stood before Emperor Palpatine. The Emperor's power probed Luke's mind, attempting to goad him to fall to the dark side, and he discovered Leia's existence. "Sister," the Emperor taunted.
However, when it comes to who Darth Vader hates more than anyone in the Star Wars galaxy, himself and Obi-Wan Kenobi don't hold a candle to the true point of Darth Vader's hatred, Emperor Palpatine. Star Wars: Darth Vader #39 by Marvel Comics is available now. Please verify your email address.
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.
