Since Bail Organa had C-3PO's memory wiped previously in order to prevent him from spilling the secret of Leia's parentage, it could be that this was a semi-regular occurrence for the droid given he couldn't be trusted to keep quiet about things.
Due to Threepio's talkative nature, Senator Organa made arrangements for the protocol droid to receive a memory wipe in order to keep Leia's true parentage a secret.
C-3PO served Senator Amidala during the Clone Wars who gave him new golden platings and also went on many adventures with his old counterpart R2-D2. Towards the end of the war, Anakin turned to the dark side and Padme died so her friend, Bail Organa took the droid as well as R2 when he took her daughter, Leia.
The lack of recognition could have come from an old man simply not remembering the passing droids of his youth. Lastly, Owen didn't seem the sentimental type to form any emotional attachments to droids. Being a practical man, he viewed them as tools to be used and replaced when they no longer functioned.
EXTRA footage from 1977 REVEALS Darth Vader’s Backstory
Does Darth Vader not recognize C-3PO?
in the Dark Horse comic series star Wars Tales, which is now part of legends, it's revealed that Darth Vader did recognize C. 3PO on Cloud City. when 3PO was shot by Stormtroopers, his parts were brought before Vader. because the Imperials thought he could hold valuable.
Do R2D2 and C3PO know that Darth Vader is Anakin? Threepio had his memory wiped at the end of Revenge of the Sith. He doesn't even know Anakin was Anakin.
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. Anakin Skywalker never knew Padmé was pregnant with twins, and he believed his child had died with his wife.
Vader was hunting down the pilot who blew up the Death Star, and hired Boba Fett to find them. Boba was unable to, but he did give Vader a name: “Skywalker.” This, combined with his knowing Luke was Force-sensitive and had been trained by Obi-Wan, was what made him realize the truth.
The base assumption of why Obi-Wan doesn't remember R2-D2 -- in light of the prequels -- is that Obi-Wan is feigning ignorance in A New Hope to downplay the importance of the droid's arrival.
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.
C-3PO accidentally became part of the Battle of Geonosis when his head was affixed on top of a battle droid's body after a mishap in the Geonosian droid factory. R2-D2 and C-3PO witnessed the secret wedding between Anakin Skywalker and Padmé Amidala on Naboo.
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.
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.
Why is C-3PO forbidden to translate the Sith-Runic language? Rather simple. All protocol droids have the ability to translate. But a Senate ruling put in a rule that required all translating droids to be forbidden to translate, and if such system is overridden, to erase the droid's memory.
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.
Instead of being in the life suit, Vader looks like an older Anakin who never received the devastating injuries, and Padmé and Luke (who struck down Palpatine) are by his side. It's during these visions Palpatine realizes Luke - who he only knew as the Rebel who destroyed the Death Star - is Anakin's son.
The two recognize Luke's similarities to Anakin and try to prevent him from sharing his father's fate, but they let him remain Luke Skywalker instead of having him go by Luke Lars out of respect for his grandmother, Shmi Skywalker.
Leia Organa never knew her mother Padmé - but Star Wars comics have made Padmé's memory even more heartbreaking after Rise of Skywalker. Marvel's Star Wars comics have made Leia and Padmé's relationship even more tragic. Leia Organa never knew her mother, Padmé Amidala.
Ever since Return of the Jedi, Star Wars has reframed Luke and Leia's kiss as lacking real romantic intent - something Leia did solely to get a rise out of her real love interest, Han Solo.
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.
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.
She senses Anakin when she reaches out to the pilot — and Vader realizes that Ahsoka, his former Padawan, lives on. In Season 2, Episode 18, “Shroud of Darkness,” Ahsoka's guilt manifests as a vision of Anakin, who's angry with her for leaving him all those years ago.
Vader mocked Luke for his lack of training in lightsaber combat, and he easily pulled the lightsaber out of Luke's grasp through the Force. However, before Vader could strike the unarmed Luke down, he suddenly recognized Luke's lightsaber as his own former weapon.
