In ancient times, people were often described as knowledgeable. As we all know, there was no paper in ancient times, and knowledge could only be recorded on bamboo slips. Bamboo slips vary in size, big and small, but the normal size is 25 cm. If we say how much a car can hold, we can calculate, for example, the width of bamboo slips is about 5 cm and the thickness is 1 cm. If we put them in a car the size of a single bed, a car will do.

If we calculate according to the number of words, we may have no idea about the number of words in bamboo slips. A bamboo slip can actually store about 40 words, so one car can hold 24,000 words, and five cars are120,000 words, which is almost a book about three centimeters thick.

In ancient times, there were no books like this and books for everyone's entertainment, only some literary knowledge, so at that time, a book of120,000 words had enabled you to learn almost all the knowledge. Such people were also scarce talents in ancient times. Ancient people selected national talents through examinations, and this examination system is still in use today.

The idiom "learning to be rich with five cars" is just an adjective, not just five cars. At that time, it was used to describe Hui Shi's high learning during the Warring States Period, and the word "learning to be rich in five cars" was gradually formed. Speaking of Hui Shi, he is a very famous politician, and the organizer of the joint anti-Qin movement that organized Wei Qichu's crusade against Qin at that time. He is a very shrewd person.