One of the most interesting parts of The Last Jedi for me were the reveal of what exactly happened the night that Kylo destroyed Luke's Jedi temple. For me the most interesting part is wondering what would have happened if things had played of differently, either if he hadn't gone into Ben's room planning on killing him, or if he'd gone through with it and killed him. Which was the bigger mistake? On the one hand going in there was a huge mistake, and I have to wonder if Luke could have worked with him more and prevented him from turning, and possibly used him against Snoke if he hadn't gone in there. At the same time if he had killed him, there's a pretty good chance he could have severely crippled The First Order, and possibly prevented a lot of what happened from RoTJ all the way through TLJ. There's telling what this would have done to his relationship with Han and Leia though, and I have to wonder what it would have done to him emotionally.