There is a famous remark from Abraham Lincoln “Give me six hours to chop down a tree, and I will spend the first four sharpening the axe."That's to say, sharpening your knife won't waste your time for cutting your firewood.

　　有一句名言，亚伯拉罕.林肯的“给我留个小时砍倒一棵树，我会先花四小时磨斧头。”这就是说，磨练你的刀不会浪费你的时间，减少您砍的柴火。