once upon a time, there lived an old man in Song Kingdom, who raised a lot of monkeys at home. The old man fed each monkey eight acorns every day, four in the morning and four in the evening. Later he fed so many monkeys that he had not enough acorns. So he wanted to feed monkeys seven acorns each day. Then he discussed with his monkeys, “From today on, I will give each of you four acorns in the morning and three acorns in the evening. Is that O.K.?” Hearing this, all the monkeys got angry. How come lack one in the evening? Then the old man changed to say, “I'll give each of you four acorns in the morning and three acorns in the evening.” Thinking that there were still four in the evening, all the monkeys became happy again.Three in the morning, four in the evening: The idiom originally means to fool others by playing tricks. It later extends to mean changing one’s mind frequently or not being responsible.Other expressions: to play fast and loose or to chop and change.

从前，宋国有一个老人，他在家中养了许多猴子。老人每天都会给每只猴子八颗栗子，早晚各四颗。后来，猴子越来越多，老人也越来越穷，所以他想每天只给猴子七颗栗子，于是他就和猴子们商量：“从今天开始，我每天早上给你们四颗粟子，晚上给你们三颗栗子，行不行？” 猴子们想了一想，晚上怎么少了一颗呢？于是大叫起来，非常不愿意。老人一看，连忙说：“那么我早上给你们三颗，晚上再给你们四颗，可以了吧？” 猴子们听了，以为晚上的粟子已经由三个变成四个，跟以前一样，就高兴地同意了。朝三暮四：原意是指实质不变，用玩弄手段，改换名目的方法使人受骗上当。后引申为，说话、办事反复无常、不负责任。

朝三暮四 (zhāo sān mù sì)
【翻译】Three at Dawn and Four at Dusk.
【释义】原指玩弄手法欺骗人。后用来比喻常常变卦，反复无常。
【例句】你一旦有了目标就要做下去，千万不能朝三暮四，否则最后只会一事无成。
【近义词】朝秦暮楚，反复无常
【反义词】墨守成规，一成不变，一诺千金，一言九鼎，一心一意