What I’ve come to feel, rewriting this scene, is that Kylo’s theatrical lines don’t really match up with Rey’s lines, so I think he was definitely telling her something else in an earlier version of this film, something far more personal and less expository. All of her emotional lashing out and ‘I don’t want this’ doesn’t make sense when he’s talking about some Sith or Jedi prophecy or saying that her parents were loving people who protected her from Palpatine.

So that’s why I’m heavily leaning on the idea that whatever Kylo tells her must be something highly personal to her that she fundamentally doesn’t want to believe, and he has to say this right from the start of the scene, because she almost instantly responds with a tearful ‘You’re lying’. Kylo’s lines about Rey needing to see who she was make sense, but Kylo then following that with ‘I know the rest of your story’ doesn’t seem to warrant such an extreme response from Rey. It’s like he made a direct statement about her that cuts to the core of her being.