John Boyne said this quote

“ But once, in his anger, Aidan had asked me whether I thought I had wasted my life, and I had told him no. No, I had not. But I had been wrong. And Tom Cardle has been right. For I had known everything, right from the start, and never acted on any of it. I had blocked it from my mind time and again, refused to recognize what was staring me in the face. I had said nothing when I should have spoken out, convincing myself that I was a man of higher character. I had been complicit in all their crimes, and people had suffered because of me. I had wasted my life. I had wasted every moment of my life. And the final irony was that it had taken a convicted pedophile to show me that in my silence, I was just as guilty as the rest of them. ”