The whole of life is just like watching a film. Only it's as though you always get in ten minutes after the big picture has started, and no-one will tell you the plot, so you have to work it out all yourself from the clues.
出自汉·桓宽《盐铁论·申韩》。善于治理国家的人，一发现弊病就立即补救，一看到漏洞就立即堵塞。
The most important thing in mathematics is to ask the right questions.