The end of history will be a very sad time. The struggle for recognition, the willingness to risk one's life for a purely abstract goal, the worldwide ideological struggle that called forth daring, courage, imagination, and idealism, will be replaced by economic calculation, the endless solving of technical problems, environmental concerns, and the satisfaction of sophisticated consumer demands.

孔子说：“譬如堆山，还差一筐，没堆成就停了，功亏一篑是自己造成的；譬如填坑，只倒一筐，继续填下去，坚持不懈是自己决定的。”

The best way to learn mathematics is to do mathematics.