A theory is a battlefield in your head.

Even so, there were times I saw freshness and beauty. I could smell the air, and I really loved rock 'n' roll. Tears were warm, and girls were beautiful, like dreams. I liked movie theaters, the darkness and intimacy, and I liked the deep, sad summer nights.

The thoughts that occur to me while I’m running are like clouds in the sky. Clouds of all different sizes. They come and they go, while the sky remains the same sky always. The clouds are mere guests in the sky that pass away and vanish, leaving behind the sky.

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.

Friends don't need the intervention of a third party. Friendship's a voluntary thing.

There are lots of things we never understand, no matter how many years we put on, no matter how much experience we accumulate.

Then I noticed that my shadow was crying too, shedding clear, sharp shadow tears. Have you ever seen the shadows of tears, Mr. Wind-Up Bird? They’re nothing like ordinary shadows. Nothing at all. They come here from some other, distant world, especially for our hearts. Or maybe not. It struck me then that the tears my shadow was shedding might be the real thing, and the tears that I was shedding were just shadows. You don’t get it, I’m sure, Mr. Wind-Up Bird. When a naked seventeen-year-old girl is shedding tears in the moonlight, anything can happen. It’s true.