Gu Kaizhi, courtesy name Changkang, childhood nickname Tiger Head, was from Wuxi, Jinling (present-day Jiangsu) during the Eastern Jin Dynasty. A man of many talents, he excelled in poetry, calligraphy, and especially painting, earning him the title "Three Perfections" (perfection in talent, painting, and devotion).
In his youth, Gu Kaizhi served as a military advisor to Huan Wen, the Grand Marshal of the Eastern Jin dynasty. At that time, regional warlords threatened national unity, so Huan Wen frequently led campaigns to suppress them. Gu Kaizhi accompanied Huan Wen on these expeditions for many years, earning great respect and forging a deep friendship.
Once, Gu Kaizhi accompanied Huan Wen on a large ship to Jiangling to inspect the troops. On the second day in Jiangling, local officials came to pay respects to Huan Wen and brought many bundles of the region's specialty—sugarcane. Huan Wen was very pleased and said, "This sugarcane is quite famous. Let's all have a taste together."
His subordinates each took one and began eating. As they ate, they exclaimed happily, "Truly worthy of its fame—incredibly sweet!"
At that moment, only Gu Kaizhi was lost in admiration of the beautiful scenery of Jiangling, not bothering to take any sugarcane. Huan Wen noticed this and deliberately picked a long stalk, walked up to Gu Kaizhi, and said, "Here, have one and taste it."
With that, he handed Gu Kaizhi the tip of the sugarcane. Still absorbed in the scenery, Gu Kaizhi took it without a glance and began chewing on the end.
Huan Wen saw Gu Kaizhi's eating manner, suppressed a smile, and asked, "Is this sugarcane sweet?" The people nearby also laughed and said, "The sugarcane we're eating is extremely sweet, but we wonder if the sugarcane Advisor Gu is eating is sweet or not?"
Gu Kaizhi finally snapped back to reality, realizing he had been chewing on the tip of the sugarcane and understanding why they were laughing. With a flash of wit, he raised the sugarcane and said, "What are you laughing at! I see you don't understand how to eat sugarcane at all—there's a great art to it!"
Seeing how serious he looked, everyone laughed and asked, "Can eating sugarcane really reveal anything special? Tell us, why do you start from the tip?"
Gu Kaizhi said, half-jokingly, "You start by eating the sweetest part, and as you go on, it gets less sweet, until you lose your appetite. But I start from the tip, and it gets sweeter and more flavorful—this way of eating is called 'gradually entering a delightful state.'"
Upon hearing this, everyone burst into laughter together.
Now the idiom "Gradually Entering a Delightful Realm" is often used to describe a situation that improves day by day.
Source: *A New Account of the Tales of the World*, "Taunting and Teasing"
Meaning of the Idiom: Later, the Chinese idiom "渐入佳境" came to describe a situation that improves day by day.