What is an identity? It isn't something you can hold in your hand. There is no tangible equivalent to the ideas you hold in your head about being human. Sure, there are mirrors. You can look into them and see a physical space that you occupy, but it doesn't give any insight into the way it feels to occupy that space. The comfort of calculated movements and the feeling of being in control is something that is missing in a reflection. What happens when you lose that feeling of control? What happens when your movements don't feel like yours anymore?