When I was about 11/12.
I was standing in my old house, in the Kitchen doorway, and just watched my Stepdad and Mum having yet another 'break out' (as I called them). All this sh*t going on around me, and what had happened to me because of my Mum and Stepfather in the past (Lets not go into that, we'll be here for hours), and I just sort of snapped. Something in my brain just clicked that this wasn't how people, especially children, were meant to live. My Stepdad turned to me and made some threattening remark.
I went to bed, got up in the early hours, packed my bags, and left for my real Dads the next day.