quote:
"But the idea was that in that scene where R2 plugged in, he downloaded the archives of the Empire, which was referenced by Kylo Ren," Abrams said. Thirty-eight years later, in both our own and galactic time, that data becomes useful in The Force Awakens when a new droid approaches the dormant R2.
"BB-8 comes up and says something to him, which is basically, 'I've got this piece of a map, do you happen to have the rest?'" Abrams said. "The idea was, R2 who has been all over the galaxy, is still in his coma, but he hears this. And it triggers something that would ultimately wake him up."
The director acknowledges that R2's sudden "awakening" at the end was designed to be an emotional storytelling utility: "While it may seem, you know, completely lucky and an easy way out, at that point in the movie, when you've lost a person, desperately, and somebody you hopefully care about is unconscious, you want someone to return."
So for those let wondering: BB-8's earlier question rattles around inside R2's dome for a while. Those old astromechs must just take a while to boot up again.
Well that's kind of a disappointing answer, honestly.
So BB-8 triggered him waking up, and they just held it until the end of the movie for storytelling purposes. I understand why you do that, but if that's the only reason you did it, at least keep it a mystery for us to speculate about.
It was much more fun when we thought it could've been Luke and/or Rey, or even something else. Like Lindelof used to say about Lost, explaining mysteries kind of ruins them.