3. Why Rey Is Abandoned On Jakku - The Luke Theory
Think of the look that Luke gives Rey, right at the close of the film. You can interpret it positively if you like, but thanks to the length the shot goes on for and Hamill's brilliantly nuanced performance, the reading I get is more of regret. He looks like he's thinking "Well... you really weren't supposed to find me here", which if you extrapolate out and give it motive, could be because Luke himself left Rey on Jakku for her own wellbeing. Why? Well, think back on Luke's training under Yoda. He doesn't spend a whole lot of time under his tutelage, and whatever questions he asks as to the power of the Dark Side or just out of curiosity are quashed. He's taught the ways of the Force and the respect for its power through sheer belief that it exists, rather like how any religious teacher would reinforce their own faith. The point is; Luke is barely a Jedi Master even after all of this, he has only a handful of lessons to pass on, and during his battle with Vader he only won by embracing rage and dark thoughts for a short time. Translate that across to Episode VII and the talk of him teaching a "new generation of Jedi", and what does he have to really pass on? It's very possible that he flounders in this new role, with an impressionable set of children looking to the path Vader was on as a more purposeful way to live. Perhaps Rey was one of these students, or just his daughter who lived in the same quarters. We know that Kylo turned to the Dark Side following Luke attempting to teach what he learned, and as he watched Kylo burn the place to the ground, he could erase Rey's memory of anything Force/Jedi-related, admitting defeat in his position and placing her on Jakku for her own safety. He decides he doesn't want anything to do with the light and dark sides of the galaxy, and resigns himself to a life of isolation for the good of everyone around him... until Rey reappears and once again forces him back into play.