悔恨自己的错误，而且力求不再重蹈覆辙，这才是真正的悔悟。

What a fool old Adam was. Had everything his own way; had succeeded in gaining the love of the best looking girl in the neighborhood, but yet unsatisfied with his conquest he had to eat a miserable little apple.

The best way to predict the future is to create it.

To do mathematics is to explore a universe of ideas, where the only limit is your imagination.

The world only exists in your eyes. You can make it as big or as small as you want.