Star Wars: 10 Things You Didn't Know About R2-D2
1. He Never Had A Full Memory Wipe
R2-D2 is one of the most characterful droids in Star Wars, with lots of little quirks and idiosyncrasies that make him one of the most likeable characters in a galaxy far, far away. This isn't always the case with droids, though, and there's a very good reason for it.
Despite their level of sentience and emotional awareness which puts them almost on a par with living beings, droids don't have any say in what happens to them, and are treated something like slaves.
Their owners can do pretty much whatever they want with their property, and to keep them docile and make them easier to control, they are frequently subjected to full memory wipes which stops them from developing unique personalities. By some stroke of luck, Artoo has managed to avoid most of these memory wipes, which doesn't just mean he's got his own character, it also means he knows more about the galaxy's biggest events than most, particularly in regards to the Skywalkers.
Even C-3PO isn't so fortunate. Despite spending most of his life around the family, he had his memory wiped after The Clone Wars to prevent him spreading the secret of who Luke and Leia really were.