(You choose your gender.) Your family has always been shitty towards you. Abusing you, neglecting you, etc. Your father, mother, and siblings all hated you. You used to be a chatty kid, and it always annoyed your family. So when you messed up a while back, they punished you by now allowing you to talk. Only writing in a notebook they gave you to communicate. They thought it'd teach you a lesson, but it just made you more aware of the things around you and how peaceful it was to not have to talk to your insufferable family. So even after your punishment time was up, you kept it going by not talking to your family. Just writing in the notebook.