How is Rey so good with lightsabers?

After watching Episode VII for the third time, I realized why it bugged me that there were no records of her in Luke Skywalker's archives even though she supposedly spent twenty years training with him. How could someone like Rey, who hasn't had formal training, be better than someone like Kylo Ren, who is supposedly very skilled?

Rey is not only comfortable with a replica lightsaber; she has core memories of Anakin/Luke Skywalker wielding the weapon. Therefore, she knows how it's swung and moved through space. Also, these memories include her watching while he fought the training remote, so she knows how to block and parry. – -And, I realized it's because we don't know who her parents are! She has Jedi blood and is likely resisting the temptation to the Dark Side.

It's easy for me to buy that Rey might be Luke Skywalker's daughter or granddaughter (maybe even a clone/reincarnation?), but it isn't so easy for me to buy that she's not related to anyone in the saga. However, this would also explain why Kylo Ren was surprised by her knowledge of what went on between Luke and Ben Solo.

This fan theory might seem a bit out there, but if Rey is a Kenobi, I think it could also explain why she's so good at the Jedi Mind Trick. If her grandfather were Obi-Wan Kenobi, then it wouldn't be that big of a leap for her to have subconscious memories of being able to do this ability.

After all, who better than his grandson or granddaughter? It would also explain why Kylo Ren and Snoke are so interested in her because she could be mighty with the Dark Side.

What do you think? Is Rey Kenobi? Are there other fan theories out there about her parentage? Leave your thoughts in the comments below.

There are some theories that she's a Skywalker, Solo, or even Snoke's daughter. Also, no one knows when Episode VIII will be released, but it could be December 2017.

I've read several theories about this, but none have convinced me thus far. Yes, it would explain why she's so powerful with the Force and can use advanced abilities without being trained to do so. Still, it wouldn't describe her superhuman abilities, such as her insane lightsaber skills and skill in hand-to-hand combat. Since we know so little about her, anything could be possible...

Rey's connection to the Force is strong.

She has a deep awareness of the Force and is in tune with her surroundings. She feels Luke's lightsaber calling to her in Maz Kanata's castle, and when she touches it for the first time, she experiences a brief vision of the future. - From Wookieepedia

My theory is that Luke Skywalker trained Rey before he went into exile. They had a falling out, resulting in Rey being unable to find him. As far as we know, she didn't keep in touch with the Resistance, so they never alerted her to Luke's disappearance, likely because Poe Dameron knew that she was too upset to be told this news while she was stranded on Jakku.

It makes sense that Rey would have gone to Luke for training since he is the only person known to pull off this feat. No one has ever held their own against Kylo Ren without being trained by someone who himself has been prepared under Luke Skywalker. And I think it's safe to assume that even though Kylo Ren was Luke's apprentice, Luke never taught him the same things as he taught his other students. This makes sense with both Rey and Kylo's abilities and affinities for the Light and Dark sides of the Force.

TFA Novelization: Within a few short weeks, she had achieved more than most Jedi learners achieve in years.

I think it is easy to say that Rey was, in fact, Luke's last and most successful student before he went into exile. And with the politics of the New Republic and conflicting schedules for training new Jedi students, it makes sense that Luke would not be able to train everyone who wanted to learn. So I think it is likely that he sent Rey off to train with one of his other students, someone who had the time and ability to take on an apprentice.

Luke Skywalker (TFA) - I think this option would be highly unlikely. It makes sense for Leia to send Rey away to train under Luke, but it doesn't make sense for him to send Rey away. It would be better for Luke to take on more students so that he can rebuild the Jedi Order. His exile would not have been approved by the New Republic Senate anyway, so it would be risky and counterproductive.

Luke Skywalker (ROTJ) - Possible, but highly unlikely. The Luke Skywalker we see in ROTJ was not only very different from the young Jedi we saw in ANH (which makes sense since he grew up and had kids), but he also never mentions Rey or any other potential students to Leia. This would be like putting Chewbacca on trial for crimes he committed as a Wookiee. He's changed, and that is okay. Plus, Leia was on the Resistance base on Hoth at this point in time, meaning Rey would have to travel across the galaxy to find Luke Skywalker with no knowledge of where he is. This makes very little sense.