I am currently writing a YA novel about figuring out who you are and who you want to be. Set in the distant future our MC wakes up with most of his memory gone, to find a world that has mostly gone to shit. Most of the earths population is killed by these monsters that are roaming around. Behind large walls the cities are safe and the inhabitants live in peace and harmony. The MC starts of as a character that does not care about other than himself. He misses most of the empathy that most people have, and he hates almost everything. (Perhaps not the best way to start of a character and make the audience like him, I know, but that is some of the point. The audience is not supposed to like him from the start.) He doesn't remember much from before, and what he does remember is not good stuff. That is some of the reason that he doesn't care much. During the novel however, he turns to become more of a good guy and start caring for other people than himself. He still is no knight in shining armor at the end, but without spoiling to much, he is going through quite the change during the course of the story. This way to approach the theme, is it overused? I just read the maze runner, and it starts of quite similar. Though the overall plot is nothing like it, I can't help to see some of the same elements in play. Other stories that start with the MC having memory loss and have to figure out who he/she is: Jason Bourne, The maze runner, The lost hero, The son of Neptune.