Yes, he remembers everything about his past (just not based on reality), but he probably doesn't spend a lot of time thinking about it, and when he does, his memory of things is clouded and twisted by the lies of the sith, the dark side, and his own flawed thinking and character.
Master Qui-Gon Jinn's words echo in Vader's mind. There's no anger, nor hatred in this memory – Vader simply recalls one of the first lessons the Jedi Master slyly gave to young Anakin Skywalker.
The short answer is yes, without a doubt, Vader regretted becoming a cybernetic monstrosity. First, there's the constant pain and discomfort from his suit. Worse, however, is the psychological pain. Vader destroyed everything he had ever known for a chance to save Padme.
According to Canon, Darth Vader did see C3p0 after the droid was blasted by an off screen stormtrooper. The stormtrooper brought the wreckage of the rebel droid and ask for permission to destroy. Vader however remembered the droid from his days of slavery, and decided to return it to Chewie in good faith.
Every time she speaks, he remembers Padmé. Fighting alongside Sabé reminds him of fighting alongside his wife. While that is certainly painful enough, it's also reminds Vader of the man he used to be, a past he had long ago attempted to kill and bury. However, the memory of Padmé via Sabé won't let his past stay there.
Darth Vader Remembers Anakin Skywalker (Flashbacks)
Does Anakin regret killing Padmé?
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.
Yes, he remembers everything about his past (just not based on reality), but he probably doesn't spend a lot of time thinking about it, and when he does, his memory of things is clouded and twisted by the lies of the sith, the dark side, and his own flawed thinking and character.
Star Wars Theory: R2-D2 Didn't Know Anakin Skywalker Became Darth Vader. R2-D2 served Queen Amidala and later Anakin Skywalker, accompanied by C-3PO. Unlike the golden protocol droid, R2-D2 never had a full memory wipe, so he was well aware of all events that happened around him.
Darth Vader only learned he had a daughter in Return of the Jedi - but there's no evidence he realized she was Leia before his death and redemption. Darth Vader may have never known Princess Leia was his daughter in Star Wars and never cultivated a relationship with her, even when he was a Force ghost.
To answer the original question, I'm pretty sure that R2 never knew that Anakin became Vader. He wasn't there when Anakin was named Vader, he didn't know what happened on Mustafar. All he knew is that Anakin told R2 to stay with the ship, and that was the last time R2 saw Anakin.
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.
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.
Qui-Gon Jinn, who is considered a maverick Jedi Master by his colleagues, might have been able to keep Anakin on the path of the Jedi, had he not been killed by Darth Maul. Star Wars' Qui-Gon Jinn would have been the ideal mentor for the young Anakin.
Palpatine may still have eventually traded Dooku in for a newer apprentice, but nothing would have hindered his rise to power. Had Qui-Gon trained Anakin and kept him far from Palpatine, Anakin might have eventually died in the Clone Wars and been completely unable to fulfill any Chosen One prophecies.
[Star Wars] Qui Gon knew Anakin would have to turn to the dark side to bring balance to the force. We all know that the so called prophesy was correct (from a certain point of view) in that Anakin eventually brings balance to the force by killing the emperor and subsequently dying.
In the post-2014 canon universe, the story that reveals Darth Vader discovering Luke Skywalker's identity (and thus the fact that the Death Star's destroyer is his son) is issue 6 of 2015's Star Wars comics by Marvel, which takes place sometime shortly after A New Hope.
Han Solo marries Princess Leia and they have three children: twins named Jacen and Jaina, and a younger son named Anakin. Luke reestablishes the Jedi Order, marries a non-movie (but fan favorite) redheaded Force-wielder named Mara Jade, and they have a son, Ben Skywalker (named in honor of Obi-Wan “Ben” Kenobi).
In The Empire Strikes Back, Luke and Leia share an awkward kiss, but a deleted alternate version of this moment reveals it could have been worse. One deleted scene from The Empire Strikes Back involving Luke and Leia is much worse than their kiss in the movie.
secondly, in Legends, R2 was given programming that actually restricted him. from sharing any information with Luke or Leia. about their parents or relation to one another. this was all part of the plan. to conceal this information from the twins.
You saw how Luke's attitude completely changed when he realised that was actually Yoda and so did Yoda's behaviour. As for the r2 thing, is incredibly likely he just suspected R2 had had his memory wiped several times since they last saw each other.
R2 was later able to restore his companion during the Battle of Geonosis. After the battle, R2-D2 and C-3PO were the sole witnesses to the marriage of Anakin Skywalker and Padmé Amidala in Lake Country. After this Padmé gave ownership of R2 to Anakin while she kept 3PO.
Returning to Dagobah to complete his training, an ailing Yoda told Luke the terrible truth that Vader was his father, Anakin Skywalker. Rather than destroy his father, Luke sought to bring him back into the light. At 900 years old, Yoda passed away, telling Luke that there was another Skywalker.
Although the decision to turn to the Dark Side was Anakin's alone, the choice did not come from thin air. His natural prone to impulsivity and emotion without the support systems he needed in place made it easier for Anakin to stumble down a path of darkness.
