You might, but then again you might choose not to. I reject the idea that it's just predetermination, that undermines the concept of agency. I come from a similar or possibly worse background, I find Brievik's problems extremely relatable and thus find him extremely interesting on a personal level. On the other hand I've never initiated violence against anyone else, even though I'm a long way from being a pacifist. I have a code of conduct and while it hasn't profited it me much in material terms at least I derive moral satisfaction from it.