世态炎凉 vicissitudes of the world
Explanation
世态炎凉指人情世故的冷暖变化，常用来形容人情冷暖，世事变化无常。
The idiom describes the changing aspects of human relationships, from warmth and closeness to coldness and distance.
Origin Story
从前，有个年轻的书生，怀揣着满腹经纶去京城赶考。路上，他遇到了许多人，有的热情相助，有的冷漠旁观。考试后，他金榜题名，荣耀归乡。乡亲们纷纷前来祝贺，热闹非凡。然而，当他落第时，曾经的热情消失了，取而代之的是冷淡和嘲笑。书生亲身经历了世态炎凉，深深地体会到人心的复杂。他明白了，人生的成功与失败，会改变人们对你的态度。
Once upon a time, there was a young scholar who traveled to the capital city to take the imperial examinations. Along the way, he met many people, some warmly helped him, others indifferently watched. After the examinations, he passed with flying colors and returned home in glory. His neighbors came to congratulate him, and it was very lively. However, when he failed the next exams, he lost the initial enthusiasm and was confronted with indifference and ridicule. The scholar experienced firsthand the vicissitudes of the world and understood the complexity of the human heart. He understood that success and failure in life can change the way people treat you.
Usage
世态炎凉常用来形容社会上人情冷暖的变化，以及人们趋炎附势、见风使舵的现象。
The idiom is used to describe the changing aspects of human relationships in society, and the phenomenon of people who curry favor with those in power.
Examples
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世态炎凉，人情冷暖，让我看清了社会现实。
shì tài yán liáng, rén qíng lěng nuǎn, ràng wǒ kàn qīng le shè huì xiàn shí
The coldness of the world opened his eyes.
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他经历了世态炎凉，看透了人心的复杂。
tā jīng lì le shì tài yán liáng, kàn tòu le rén xīn de fù zá
He experienced the vicissitudes of life and learned to read people's hearts.