痛定思痛 Think deeply after the pain
Explanation
痛定思痛，就是指在经历了痛苦的事情后，认真反思，吸取教训。
‚Think deeply after the pain‘ means to reflect seriously and learn from the experience after going through something painful.
Origin Story
战国时期，齐国有一位名叫田忌的将军，他与孙膑是好朋友。一次，田忌和孙膑率领军队与庞涓率领的魏国军队交战，田忌的军队屡战屡败，损失惨重。田忌非常沮丧，他找到了孙膑，向他请教如何才能战胜魏军。孙膑说：“将军，你应该痛定思痛，仔细分析一下我们失败的原因。其实，我们并非战败，而是战术失误，没有充分利用我们的优势。”田忌认真地听了孙膑的分析，终于明白了失败的原因。他根据孙膑的建议，调整了战术，最终战胜了魏军，取得了胜利。
During the Warring States Period, there was a general named Tian Ji in Qi, who was good friends with Sun Bin. Once, Tian Ji and Sun Bin led their troops to fight against the Wei army led by Pang Juan. Tian Ji's army was repeatedly defeated, suffering heavy losses. Tian Ji was very discouraged and sought Sun Bin's advice on how to defeat the Wei army. Sun Bin said: “General, you should think deeply and carefully analyze the reasons for our failure. In fact, we were not defeated, but made tactical mistakes and did not make full use of our advantages.” Tian Ji listened carefully to Sun Bin's analysis and finally understood the reasons for his failure. He adjusted his tactics based on Sun Bin's suggestions and finally defeated the Wei army, winning the victory.
Usage
痛定思痛，常用于表达经过痛苦的经历后，认真反思，总结经验教训，并从中吸取教训，避免再次犯错。
‚Think deeply after the pain‘ is often used to express that after going through a painful experience, one reflects seriously, summarizes lessons learned, and draws lessons from them to avoid making the same mistake again.
Examples
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经历了这次挫折，他痛定思痛，决定重新开始。
jing li le zhe ci cuo zhe, ta tong ding si tong, jue ding chong xin kai shi.
After experiencing this setback, he thought deeply and decided to start over.
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痛定思痛之后，他吸取了教训，避免了再次犯同样的错误。
tong ding si tong zhi hou, ta xi qu le jiao xun, bi mian le zai ci fan tong yang de cuo wu.
After much reflection, he learned from his mistakes and avoided making the same mistake again.