Despite acting as if he did not know the astromech droid, one theory holds that Obi-Wan Kenobi recognized R2-D2 in Star Wars: A New Hope. During Obi-Wan’s first meeting with Luke Skywalker in A New Hope, Luke explained that he was trying to return R2-D2 to his owner, Obi-Wan Kenobi. Since Obi-Wan had been in hiding, going by the name Ben Kenobi, he admitted that he was actually Obi-Wan. However, he denied owning R2-D2, acting as if he was not familiar with the droid.
When the first Star Wars movie premiered, none of the years of history and lore between Obi-Wan and R2-D2 was known, so this reaction made sense. However, the Star Wars prequel trilogy and the animated series Star Wars: The Clone Wars changed this. Throughout these stories, Obi-Wan frequently fought alongside R2-D2. Starting with Star Wars: Episode III - The Phantom Menace, Obi-Wan and R2-D2 helped free Naboo from the Trade Federation’s invasion. Later, both served in the Clone Wars with R2-D2 assigned to Jedi Knight Anakin Skywalker. Since Obi-Wan and Anakin often fought together, Obi-Wan was friends with R2-D2 as well. This means that although R2-D2 might not have immediately recognized Obi-Wan on Tatooine due to his age, Obi-Wan should have recognized the droid.
Related: Star Wars Confirms Yoda Recognized R2-D2 On Dagobah
This connection between Obi-Wan and R2-D2 created a plot hole that has puzzled viewers for years. However, one theory argues that Obi-Wan did recognize R2-D2, but he chose to pretend not to in order to avoid telling Luke the full truth. This would explain certain signs of familiarity between the Jedi and the droid and fit Obi-Wan’s pattern of subtly lying to Luke.
According to one article (via Looper), Obi-Wan recognized R2-D2 but simply
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