During the Five Dynasties period, a man from Heyang named Li Shouzhen was cunning and unruly from a young age, refusing to be disciplined. He later joined the army as a junior officer and caught the eye of Emperor Gaozu of the Later Jin, steadily rising through the ranks.
After a battle against the Khitan, he was defeated and surrendered, then began fighting for the Khitan. He often rode a tall horse, strutting about arrogantly, while everyone in the market pointed at his back and cursed him; yet he remained shameless, showing no sign of guilt.
While en route to Wenyang under Khitan orders, the general unexpectedly encountered the Jin founder entering Bianzhou. Filled with dread, he was forced to pay court, feigning submission.
Soon after the death of Emperor Gaozu of the Later Jin dynasty, Li Shouzhen grew increasingly restless, secretly harboring treacherous ambitions. He bribed powerful ministers, reinforced city walls, and expanded his army, preparing for rebellion at any moment. A monk skilled in divination and physiognomy examined Li Shouzhen's face and declared, "Your features bear the mark of imperial nobility." This fueled his wolf-like ambition even further. Believing the time and circumstances favored him, Li Shouzhen secretly allied with bandits, raised troops to seize Tong Pass, and openly raised the banner of revolt.
Soon after, the imperial court dispatched Bai Wenke to lead an army to suppress the rebellion. Li Shouzhen, confident that many of the imperial troops had once served under him and held him in high regard, boasted, "I won't need to lift a sword—they'll open the city gates and welcome me themselves."
But when the two armies faced off on the battlefield, his former subordinates refused to acknowledge him, shouting curses at the rebel and listing his many crimes. This left the rebel Li Shouzhen deeply disappointed.
Later, the idiom "greatly disappointed" came to mean that one's original hopes were completely dashed, i.e., very disappointed.
Source: *Old History of the Five Dynasties*, "Book of Han," "Biography of Li Shouzhen"
Meaning of the Idiom: Later, the Chinese idiom "大失所望" came to describe how one's original hopes were completely dashed, i.e., very disappointed.