There are certain things that we cannot make ourselves believe， no matter how hard we try.

If not now, when? If not me, who?

The language of mathematics is universal, and it is through this language that we can communicate the most profound truths of the universe.

Don't cry， I'm sorry， you must understand， I am sorry to deceive you so much， but this is life.

For every dollar you spend purchasing something substantial， expect to pay a dollar in repairs， maintenance， or disposal by the end of its life.