Meng-tz lived during the Warring States Period. He was not only very knowledgeable but also very eloquent. He often used very vivid analogies to persuade kings of that period to do good deeds.

Everyone said that the king of Ch'i was stupid, without his own ideas, and easily influenced by his wicked ministers. This greatly displeased Meng-tz, so he went to the king and said, "Don't think I'm saying you're not intelligent. Everyone knows that plants all need sunlight to grow. If you expose them to sunlight for a day, and then keep them in dark for ten days, even those plants which grow easily will not do well. In the same way, the time that I am here with you is not very long. You may develop the will to do good things, but then as soon as I leave, those other people come and lead you astray, and the good will which had just begun to sprout is again destroyed." Following this, Meng-tz drew several more analogies, urging the king to completely devote himself to governing his country.

This idiom is now often used to describe a situation in which a person is trying to learn a thing, but rarely practices.

春秋战国时期，出现许多家学派，他们各自坚持自己的主张，并到各国游说，宣传自己的学说。这些人不但学问高深、知识丰富，而且能言善辨，往往能说服执政者改变主意。

孟子是当时有名的一位辩士，他帮助齐王施政，看到齐王昏庸、没有主见、轻信小人谗言，很不满，就不客气地对齐王说：“大王，您太不明智了！天下虽有生命力 很强、很容易生长的植物，但如果把它放在太阳底下晒一天后，再放在阴寒的地方冻上十天，它还能存活吗？我在大王身边的时间很短，即使您接受我一些好的建 议，有了一点从善的决心，但只要我一离开，那些奸臣就会在您面前唱反调，哄骗您，大王又常常轻信他们的谗言，这样怎么能让我有成就呢？”他又作了一个比 喻：“下棋是件小事，但如果不专心，同样学不好。奕秋是全国最会下棋的高手，他有两个徒弟。其中一个非常专心学习下棋，处处听从奕秋的指导；另一个心不在 焉，一直想着用箭射空中的天鹅。同一个老师，同时学习，但两人的成绩却相差很多。这不是他们的智力不同，而是专心的程度不一样啊！”

孟子用了两个比喻告诉齐王做事情要有恒心，要专心，否则是不会成功的。

一曝十寒 (yī pù shí hán)
【翻译】One Day of Sunlight Followed By Ten Days of Cold.
【释义】曝：晒。原意是说，虽然是最容易生长的植物，晒一天，冻十天，也不可能生长。比喻学            习或工作一时勤奋，一时又懒散，没有恒心。
【例句】一个人做事情如果总是一曝十寒，是永远也做不了大事的。
【近义词】三心二意、有始无终、为德不终
【反义词】持之以恒、有始有终、有头有尾