"And what if that someone was your family?" Sonia's lips compress in dismay, shaking her head again, because he doesn't understand, or -- maybe she doesn't. "Someone you might affect by changing the course of things, or... God. It's not that I don't believe in the possibility that you could change a future you already know about. But that knowledge, that...that possesses you. If there's something in your future you want to change, something you want to achieve or avoid that you didn't according to some time-traveler, then that...that just becomes the center of your life. Doesn't it? I can't think of a more miserable waste of a life than that. I'd miss out on this whole other life I could be living. On all the discovery of not knowing what's going to happen tomorrow."