Is it an idiom in historical stories that Handan is a toddler, giving up everything, and gilding the lily?

Yes, they are all idioms.

Handan toddler, also known as "Handan toddler", comes from "Zhuangzi Qiushui": "I wonder what Fu Shouling learned in Handan? If you can't get the power of the country, you will lose your reason and go straight to your ears. " Hanshu records: "There used to be a toddler in Handan who lost his beard, and then he lost his old step and climbed back to his ear." At first it was a metaphor for blindly imitating others. Instead of learning the strengths of others, I lost my own characteristics. Later, it was used as a metaphor to imitate others, but it lost its original strengths.

In ancient times, agriculture was the foundation, and industry and commerce were the purpose. Is to abandon agriculture and go into business Abandon the root of things and pursue the details of the side. Metaphor does not pay attention to the fundamentals, but only to the details. [1] Idiom dictionary.

The idiom story Wang Xizhi, a famous calligrapher in the Eastern Jin Dynasty, began to practice calligraphy at the age of seven. He practices calligraphy very hard. He often practices calligraphy by the pool, and the water in the pool is dyed black. At the age of 33, he wrote Preface to Lanting Collection, and at the age of 37, he wrote Huang Tingjing. Later, due to the replacement of the writing board, the craftsman found that Wang Xizhi's brushwork was very strong, and the handwriting had penetrated into the board for three minutes.

[1] gild the lily comes from the idiom "If there is a temple in Chu, give people wine.". Scheeren said to each other,' A few people don't drink enough, but one person drinks enough. Please draw a snake and the first snake will drink water. If a snake comes first, I can draw out the wine and drink it. I drew a snake with a cup in my left hand and said,' I can do it.' Before it was done, a man's snake was done. He grabbed it and said,' A snake is not enough. Can Zi An do it? Then drink its wine. Who is the foot of a snake, who will eventually die of his wine "is a metaphor for gilding the lily." It is not only useless but also inappropriate to do something superfluous. It is also a metaphor for fictional facts.