"No, I mean..." Dexter shook his head. "It has nothing to do with the rest of it. It has nothing at all to do with any of it. And it doesn't even really have anything to do with want."
Oh, how best to explain? Dexter supposed just saying it was the only way.
"I'm not capable of doing it." He sighed. "I can't be what you need me to be. I literally do not have it in me."