According to a book written about George Lucas’ Star Wars Original and Prequel Trilogies, the creator of the franchise had a theory on who was the narrator of the Star Wars story…
In a book written by Chris Taylor, titled How Star Wars Conquered the Universe: The Past, Present, and Future of a Multibillion Dollar Franchise, published in 2014, but recently brought to light by website i09, Star Wars creator George Lucas had a theory on who actually told the story of Star Wars.
"“The entire story of Star Wars is actually being recounted to the keeper of the Journal of the Whills—remember that?—a hundred years after the events of Return of the Jedi by none other than R2-D2.”"
It all makes sense, if one thinks about it. R2 is the only droid that we know about, that has never had his memory wiped. His long-time traveling companion — C-3PO — had his memory wiped at the end of Star Wars Episode III: Revenge of the Sith. There’s also the fact that Threepio wasn’t fully finished in Episode I: The Phantom Menace, as young Anakin Skywalker was still working on him.
There’s also the fact that in every Star Wars film — with the exception of the recent Star Wars: The Force Awakens — Artoo was very prominent in every aspect of the story. Taylor (the author) writes that it would explain why the little astromech is always so heroic. R2-D2 saves the lives of just about every important character (important to the story) in all six films, and he rarely makes a mistake.
i09 makes an astute observation here:
"“In a saga that’s full of flawed characters who screw up constantly, Artoo is always right. Maybe because he’s the narrator, according to George Lucas.”"
It actually fits together quite nicely. And, considering the fact that BB-8 and C-3PO could have told R2 about the events of The Force Awakens, he still could continue his role as the narrator of the saga. So, imagine the final scene of Episode VII, and Rey is departing the Millennium Falcon. Who is watching her climb the stone path leading to the Jedi Temple and Luke Skywalker? Why it’s none other than R2-D2 (accompanied by Chewbacca of course). Now, please excuse me while I adjust my mind, it’s been blown to bits.