She gave me this look – she might have been watching from a lifeboat as the ship went down. Or maybe it was the other way around.

Math is like water. It has a lot of difficult theories, of course, but its basic logic is very simple. Just as water flows from high to low over the shortest possible distance, figures can only flow in one direction. You just have to keep your eye on them for the route to reveal itself. That’s all it takes. You don’t have to do a thing. Just concentrate your attention and keep your eyes open, and the figures make everything clear to you. In this whole, wide world, the only thing that treats me so kindly is math.

You've already decided what you're going to do, and all that's left is to set the wheels in motion. I mean, it's your life. Basically, you gotta go with what you think is right.

Genius or fool, you don't live in the world alone. You can hide underground or you can build a wall around yourself, but somebody's going to come along and screw up the works.

She curled up and pressed her cheek against his chest. Her ear was right above his heart. She was listening to his thoughts. "I need to know this," Aomame said. "That we're in the same world, seeing the same things.

No matter how honestly you open up to someone, there are still things you cannot reveal.

You’re optimistic one moment, only to be racked the next by the certainty that it will all fall to pieces. And in the end it does.