Star Wars: The Last Jedi - 8 Major Plot Theories You Need To Know
7. The Source Of Rey's Force Powers Is Luke
One of the biggest questions about Rey is exactly how she becomes so powerful in such a short period of time. She goes from being a non-Force user to one of the most powerful Jedi we've ever seen, in a matter of days. How does this happen?
Maybe Rey is just an exceptional case, which is plausible enough, but a deeper explanation can be found by examining the relationship between Rey and Luke.
In The Last Jedi, we learn that Luke has been cut off from the Force for a while, leaving his power untapped. But because the Force is all about balance - equal amounts of light and dark - that power can't just sit there while Kylo Ren and Snoke set about dominating the galaxy.
So, the Force reaches out to Rey, using Luke's blue lightsaber as a way to call out to her (when she visits Maz Kanata's castle in The Force Awakens).
Rey then touches this lightsaber and the power that should be Luke's begins to channel itself through her. This explains how she's able to resist Kylo Ren's interrogation shortly after, and why she never displayed any Force powers before interacting with the lightsaber.
Flash-forward to The Last Jedi, and Luke continues to distance himself from the Force, allowing Rey to grow stronger and stronger. Because Luke is no longer using his power, the Force has to balance things out, choosing Rey as the one to bring the light side up to meet the dark.
Notice that when Luke begins to use the Force again at the end of The Last Jedi, Rey is not using her powers at all - she's flying the Falcon. But when Luke fades away, Rey is shown using the Force to lift the rocks. Is she just channeling Luke's untouched power?
Power transfer hasn't been discussed in the Star Wars movies so this theory has no canonical basis, but it does explain how Rey becomes so powerful so quickly.