Early on in the film, we see Rey being adorable in her X-Wing pilot helmet.
I remembered seeing the numbers “733” on her helmet on my first viewing.

But then I realized it wasn’t “733”, it was Aurebesh.

The supplementary materials, specifically the TFA Visual Dictionary and Rey’s Survival Guide, shed more light on this.

She finds a crashed X-Wing, it belonged to a squadron called the Yellow Aces.
She finds a pilot helmet, belonging to a Dosmit Ræh of the Tierfon Yellow Aces.

                     
She makes a doll of an X-Wing pilot by hand,

she enjoys wearing the helmet and, at least when she was younger, liked to pretend she was Ræh, X-Wing pilot. 

”You can get a clue to what happened to these fighters based on whether the
ejection seat’s inside or not.” This will be important to my next post but I figured I’d mention it while we’re here.

She runs flight simulators scavenged from downed ships and practices them during her limited free time.

”THANK YOU YELLOW-4!!!”
Now I know that you’re thinking, “sure, it says Yellow, but that doesn’t mean it’s Tierfon Yellow Aces.”

On the left you’ll see:
Flight computer–capacitors and memory drive salvaged, 2 portions, transponder ID says fighter was Yellow-4 (Tierfon)

At the top you’ll see:
“Canopy–missing (ejected)” “Cockpit–ejector seat fired”
So we know Dosmit Raeh likely survived and, if still alive, is likely still on Jakku.

”Don’t miss the repulsor lifts–I scavenged a bunch of those for my
speeder.”
Rey used primarily X-Wing parts for her personal speeder, most importantly the steering and engines, indicating familiarity with
those parts.

These are all facts from Rey’s Survival Guide and the TFA Visual Dictionary.

Rey searches probably hundreds of downed ships, and dozens of X-Wings, so why
does this book keep mentioning this one? Why does it tie everything together?
And why on earth would you give this character the name Raeh if you
weren’t going to do anything with it? Well we’ll get into more of this later but for now the important thing is Rey taking the identity of Ræh from a young age, and choosing to use that name as her own.

When Finn (who also doesn’t have an actual name) asks her for her name she replies “I’m Rey”, not “My name is Rey”. It’s a tiny detail and much too little to be theorizing from but wouldn’t it be great if both Rey and Finn at that moment were using names they adopted, not ones they were born with? And Rey instead of saying her name is Rey, responds with a simple “I’m Rey”, because that’s the identity she’s chosen, she is Ræh.
Also keep in mind that this happens immediately after Rey flies the Falcon, and is even excitedly telling Finn how she’s never flown like that before. She’s never felt more like Ræh, Ace pilot, than in this moment, and so when asked who she is, she uses the identity she took as a child, which now seems more apt than ever. 

(Credit and thanks to @harquinns for the beautiful gif at the start, and to @expelumos​ for the black and white gifs at the end, they were the only ones I could find that show that very important hesitation just before Rey says her line in the 4th gif, almost as if she’s about to say something different at first)