Chinese Idiom：胸有成竹（xiōng yǒu chéng zhú）

In the Song Dynasty (sòng cháo 宋朝), an artist called Wen Tong (wén tóng 文同) was especially fond of drawing bamboos. He planted a lot of bamboos in his garden so that he could observe the process of their growth and appearance in different seasons. He knew bamboos so well that whenever he took up the paintbrush he already had a picture in his mind, and thus he could always paint bamboos in a vivid and lively way.

This idiom is used to indicate having a well-thought-out plan already before one sets out to do something, making success assured.

北宋画家文同，字与可。他画的竹子远近闻名，每天总有不少人登门求画。文同在自己家的房前屋后种上各种样的竹子，无论春夏秋冬，阴睛风雨，他经常去竹林观察竹子的生长变化情况，琢磨竹枝的长短粗细，叶子的形态、颜色，每当有新的感受就回到书房，铺纸研墨，把心中的印象画在纸上。目积月累，竹子在不同季节、不同天气、不同时辰的形象都深深地印在他的心中，只要凝神提笔，在画纸前一站，平日观察到的各种形态的竹子立刻浮现在眼前。所以每次画竹，他都显得非常从容自信，画出的竹子，无不逼真传神。当人们夸奖他的画时，他总是谦虚地说：“我只是把心中琢磨成熟的竹子画下来罢了。”有位青年想学画竹，得知诗人晁补之对文同的画很有研究，前往求教。晁补之写了一首诗送给他，其中有两句：“与可画竹，胸中有成竹。”
典出宋·苏轼《文与可画筼筜谷偃竹记》

胸有成竹 (xiōng yǒu chéng zhú)
【翻译】Having Had Ready Plans Or Desingns In One's Mind.
【释义】原指画竹子要在心里有一幅竹子的形象。比喻做事前已有成熟的计划。
【例句】他做事永远一副胸有成竹的样子。
【近义词】成竹在胸