Sima Guang was a famous politician in the Northern Song Dynasty and a great scholar at that time. His historical work "Zi Tongzhi Jian" has been passed down through the ages and has far-reaching influence.

When Sima Guang was a child in a private school, he always thought he was not smart enough. He even thinks his memory is worse than others. In order to train his memory, he often spends two or three times more time memorizing and reciting things in books than others. Whenever the teacher finishes reading this book, other students can recite it after reading it for a while and then run out to play. Sima Guang stayed at school alone, closed the window, and continued to read and recite carefully until he understood everything, closed the book and recited it word by word.

He also used all his spare time, such as riding a horse, or when he couldn't sleep at night, while meditating and thinking about the content of the article. Over time, not only can he memorize what he has learned, but his memory is getting better and better. What he learned when he was young will never be forgotten. He studied meticulously and worked hard since childhood, which laid a solid foundation for his later writing.

Sima Guang devoted himself to research and writing all his life, often forgetting hunger, thirst, cold and heat. Where he lives, apart from books, there are only simple furnishings: a bed, a coarse quilt and a pillow made of logs.

Why use logs as pillows? It turns out that Sima Guang often studies late. When he is tired of reading, he will sleep for a while, but when he sleeps, he will turn over. When he rolls over, the pillow will roll to one side, and then his head will touch the board. Such a vibration will wake him up. So he immediately put on his clothes, lit a candle and continued reading. Later, he took the log pillow as a thoughtful thing and named it "police pillow".

It is with this spirit of never being complacent and never slacking off that Sima Guang and his assistant spent 19 years compiling the historical masterpiece Zi Tong Zhi Jian.