There was a conversation about whether the trauma he went through triggered this behavior, or if he also went through something similar when he was younger, or does trauma just make what is already inside of you worse?
I think one of the survivors talks about that on Confronting Columbine...
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"And you know, you know, you know, this can be beautiful, you say you're numb inside, but I can't agree. So the world's unfair, keep it locked out there. In here it's beautiful."