Kylo Ren has an official backstory, which involves him being shipped off to Luke’s Jedi Academy, his angst and frustration at trying to live up to his large legacy, and more than a little bit of big Dark Side intervention from the baddies of the Star Wars sequel trilogy. In Adam Driver’s mind, that story was a bit more simple and grounded. There are hints of this in the Star Wars expanded canon, about Han Solo’s drifting back to his old life and Leia being absorbed by the pull of her role as a famous rebel and senator and then rebel again.