During the Three Kingdoms period, a man named Guan Lu showed remarkable talent from childhood. Diligent and quick-witted, he had a particular passion for astronomy. By age fifteen, he had mastered the *Book of Changes* and become skilled in divination, gradually earning a reputation.
As time passed, the story reached the ears of He Yan, the Minister of Personnel, and Deng Yang, the Imperial Advisor. On the twenty-eighth day of the twelfth lunar month, after a hearty meal, the two bored officials summoned the fortune-teller Guan Lu to perform a divination for them.
Guan Lu had long heard that these two were trusted confidants of Cao Shuang, a grandnephew of Cao Cao, who abused their power and had a terrible reputation. After a moment's thought, he decided to seize the opportunity to teach them a harsh lesson and cut them down to size.
He Yan, upon seeing Guan Lu, exclaimed loudly, "I hear your divinations are very accurate. Quickly cast a hexagram for me and see if I'll have another chance at promotion and wealth. Also, these past few nights I've dreamed of flies always landing on my nose—what omen is this?"
Guan Lu thought for a moment and said, "In the past, the Duke of Zhou was loyal and upright, assisting King Cheng of Zhou in establishing the state and ensuring peace and prosperity. Now your position is even higher than the Duke of Zhou's, yet few are grateful to you while many fear you. This is likely not a good omen. According to divination, your dream also portends misfortune."
Guan Lu continued, "To turn misfortune into good fortune and avoid calamities, one must emulate great sages like the Duke of Zhou, cultivate a kind heart, and perform good deeds." Deng Yang, listening nearby, strongly disagreed and shook his head repeatedly, saying, "These are all platitudes, nothing meaningful."
He Yan's face turned ashen, and he remained silent, not uttering a single word.
Guan Lu laughed heartily and said, "Though it's a cliché, it should not be taken lightly!"
Soon after, the New Year arrived, and news came that He Yan, Deng Yang, and Cao Shuang had been executed for rebellion. Upon hearing this, Guan Lu repeatedly said, "They ignored the common truths I spoke of—no wonder they met such an end!"
Later, the idiom "a platitude" came to refer to the oft-repeated sayings of old scholars, meaning something stale and unoriginal. It is a metaphor for words that have been heard so often they become tiresome.
Source: *Records of the Three Kingdoms*, "Biography of Guan Lu"
Meaning of the Idiom: Later, the Chinese idiom "老生常谈" came to describe a platitude came to refer to the oft-repeated sayings of old scholars, meaning something stale and unoriginal. It is a metaphor for words that have been heard so often they become tiresome.