In the late Northern Zhou (beǐ zhōu 北周,557-581AD) era,after the emperor Xuan Di (xuān dì 宣帝) died from disease,his prince took the throne later as the king of the country was very very young,hence needed someone to sponsor him. An ambitious and capable minister named Yang Jan (yáng jiān 杨坚) was qualified for this critical position,and before long,he became the actual regent of the hole government.

In the Spring and Autumn Period (chūn qiū 春秋时期,770-476 BC), in the State of Qi there was a man who always let his imagination run away with him. One day he even worried that the sky would falll on his head. He was so worried that he could neither eat nor sleep. Later, someone persuade him that his fears were groundless.This idioms satirizes those who worry unnecessary.

During the Northern Dynasties Period, there lived a man named Li Mi, who from his youth studied under Kung Fan. Kung Fan was both very knowledgeable and morally upright. He taught his students to be conscientious and responsible. Before each lecture, he would first thoroughly research his subject, and then teach his students everything that he knew. He had very high hopes for his students, especially in the area of morality, and controlled them very rigidly.

Once, Wu Zetian received a letter which informed against Zhou Xing. The letter aside that Zhou Xing was plotting a rebellion in collaboration with others. Wu Zetian was furiously angry when she read the letter, and immediately ordered Lai Junchen to deal with the case severely. Hearing the order, Lai Junchen had misgivings about it. He knew that Zhou Xing could not be forced to tell the truth merely by using a letter informing against him because he was very sly and crafty. Lai Junchen also knew that he would not be for given if he should fail in dealing with the case, because the empress would certainly blame him and punish him. How could he solve the problem then? He turned the problem over and over in his mind, and finally thought out a "brilliant scheme".