The best prophet of the future is the past.

失去某人，最糟糕的莫过于，他近在身旁，却犹如远在天边。

Never stop learning; the world is always changing.

The beauty of life is, while we cannot undo what is done, we can see it, understand it, learn from it and change. So that every new moment is spent not in regret, guilt, fear or anger, but in wisdom, understanding and love.

In mathematics, the simplest questions often lead to the most profound discoveries.