When C3PO sacrificed his memory banks to help Rey get vital information she needed in Star Wars: The Rise of Skywalker, there weren’t too many people out there who didn’t think that they’d find some sort of fix for it before the end of the movie. The fix turned out to be his trusty pal, R2-D2, who simply just uploaded the droid’s memory back-up, bringing up back up to just shortly before the events of The Rise of Skywalker.
Walking out of the theater, a lot of people were left with a whole new question. How much of C3PO’s memory was actually restored? After all, this wasn’t the first time that the character’s memory was wiped. For episodes 4-9, he had no memory of anything that took place during the prequel trilogy. Did this new restore just restore that chunk, or did it give him back the whole thing? Well, now we’ve got an answer thanks to the junior novelization of the movie by Michel Kogge. Here’s the relevant passage from the book:
This caused a memory file that R2-D2 had restored to be accessed and read. It was a record of the moment when C-3P0’s maker had fitted a photoreceptor into his eye socket and he had experienced the visual spectrum for the first time. The initial image his photoreceptors had captured was of a blue-and-white astromech.
According to the new rules these books are all considered canon. So, that means C3PO now has his whole memory back, from the moment young Anakin popped his eye in until the end of The Rise Of Skywalker.