Who is the protagonist in the memoir, We Are Not Broken?

Matt Johnson is the protagonist of the memoir, and the memoir is written from their first person perspective. The author George identifies as non-binary but refers to themselves in the memoir as a boy, or as a brother. Johnson explains “Although my real name is George, growing up I went by my middle name, Matt (as Nanny used to say, ‘I’m not calling no little baby [italicized] George’)”