This really had a profound effect on me:

"It really messes you up," he said. "It's incomprehensible the way human beings can slaughter each other in front of you. And you take it home with you. And it's like you haven't cleaned your teeth in several months, it leaves a bad taste in your mouth."

It's almost impossible to be empathetic and try to understand what McCullin must be going through... Wow.