Also, big shout-out to /r/FanTheories, whose twisted/brilliant minds never cease to amaze.
This was supposed to be the big moment. The entire reason for the Star Wars prequel trilogy to exist -- besides selling a shitload of toys -- was getting to see the origin of Darth Vader. And we did in fact get our climactic showdown between Obi-Wan and Anakin. Maybe it went on a little too long, but a balls-out laser sword fight on a lava planet is still a balls-out laser sword fight on a lava planet. We all knew that Anakin had to end up disfigured and/or dismembered before the movie ended, and that happened too. But after Papa Palpatine scooped up his apprentice and Robocop'd him up, everything went wrong.
It's hard to forget what happened when Anakin woke up as Darth Vader, that first gutteral cry when he heard Padme had passed away.
I know, you can already hear it in your head, but go ahead and listen to it again. It's just as bad as you remember it. The line is so goofy, the timing so awkward and the staging so steeped in over-the-top melodrama that you can't help but laugh. In the halls of Cheeseball Movie Moments, you can find that GIF near the front, encased in carbonite.
Like some of the best fan theorists out there, Reddit user spikesya managed to turn this entire scene on its head, transforming it from Mystery Science Theater fodder into something much more somber and poignant. It centers on the cyborg nature of post-Revenge-of-the-Sith Vader.
Ani was in piss-poor shape after Obi cut him down. When Vader was referred to as "more machine than man," it was meant literally. Though the cybernetic limbs are undoubtedly handy, the vocal modulation was probably the biggest improvement. Darth Vader's iconic helmet transformed Anakin's voice from angsty emo to the Robot Mufasa we know and love. But that upgrade came at a price. Since we know Anakin doesn't actually sound anything like James Earl Jones (also evidenced later at the end of Return of the Jedi, with the reveal of the Pasty Eggman underneath), we can assume some sort of automated computer is filtering his voice. It seems likely that Vader's vocal chords were damaged enough that the suit has to do some of the interpretation work, getting words from Vader's mouth and then spitting them out in a more audible manner. Sort of like if Google Translate and Siri worked together to not totally suck for once.
On most occasions, this technology should prove to be pretty useful. But what would Vader's voice computer do when faced with an unintelligble scream of unimaginable pain? Well, it would probably attempt to translate that raw emotion into "NOOOOOOOO!!" If this is true, that would mean that Vader didn't say that word, but the machine chose to say it for him. As spikesya notes, it's pretty tragic to imagine an Anakin so far from humanity that he can't even properly express all of his anger and guilt and sorrow -- all the things that drove him to the Dark Side to begin with.
And then there's the bit where that "NOOOO!!" was added to Return of the Jedi for the Blu-Ray release. There's no fan theory there -- that's just George Lucas fucking with us.
There are tons of theories out there about who Rey really is, but most of them boil down to her being related to Luke and Leia. Either she's Han and Leia's second child or Luke's long-lost daughter or even a female Skywalker clone -- but that's not what we're here to talk about. The theory, brought up by echof0xtrot, suggests that Han knew all along that Rey was family, and feels an obligation to help her. We get tons of clues and hints throughout The Force Awakens that suggest as much.
Let's think about how Rey and Han meet up. It just so happens that the Millennium Falcon is on Jakku, and it just so happens that they instantly run into Han after escaping The First Order. This series of events seems super convienent and a little too lucky, even for a universe with a mystical energy field that controls everyone's destiny. Instead, let's consider another scenario; remember that bit in Rey's lightsaber-induced vision, when she sees her young self? While a ship flies off into the distance, sweet Baby Rey is left on Jakku in the hands of that disgruntled alien Gamestop employee who buys scrap for food portions.
That's the same alien who yells after the Falcon, "That's my ship!" like he had spent the last 30 years of his life keeping it in his garage and rubbing it with a diaper. Why would that Plus-Sized Watto be left with Rey? Well, maybe someone gave him the Falcon in exchange for his silence about Rey's location. This whole time, Han has been keeping tabs on his daughter (or niece), watching over her. Those lines about it being sold from place to place was all bullshit. Hell, he probably had the Falcon equipped with some sort of tracker -- that's why they were able to grab it immediately.
Next time you see Force Awakens, pay attention to what Han does and says around Rey. The first time he sees her magically fix his ship, Han just gives a quick "Huh," and then bolts -- and then rushes over to Finn and gives him an extra pat on the back for helping Chewie. Han doesn't want Rey to know what he knows, so he tries not to show her any undue affection; of course, he overcompensates by blowing her off completely. Han is definitely keeping something close to that classic black vest of his.
But Han still cares for Rey, deeply. That's why he offers her a job on the Falcon -- he's going to take her away from the dangers of the war. If you think about it, Han doesn't have any skin in this game -- he and Leia have long been estranged, and he knows Luke can handle himself. More than anyone else in the movie besides maybe Chewie, Han feels a connection (and responsibility towards) Rey.
He probably feels tremendous guilt about leaving his kin all alone on that sub-Tatooine shithole. When they arrive on Takodana, Rey says "I didn't think there was so much green in the whole galaxy," and Han looks down in shame.
Papa-Uncle Solo feels awful because he doomed Rey to live out on a desolate rock in the middle of nowhere; protecting her has meant preventing her from experiencing much of a life at all. Rey is capable of so much more, and he knows it. You can see the look of pride on Han's face when he and Finn find Rey escaping on the Starkiller, without anyone else's help.
Now, we all know that Han is currently resting at the same ambiguous bottomless pit that the Emperor (and Gaston) fell into, so he won't be able to tell us for sure what he knew. But let's be real: Han in the Force Awakens is basically Obi-Wan. He's the wise old coot who explains the way of the world to the youngsters, only to die at the end of the movie so the heroes can prove themselves without the crutch of a mentor. This wouldn't be the first time someone in a Star Wars movie was secretly watching over a talented youth, only to die without ever revealing that they weren't telling the truth the whole time. It's like poetry, sort of. It rhymes.