This sentence comes from Han Yu's understanding of learning, which means that learning is proficient because of diligence, but it can be abandoned in games and play. There is another sentence below this sentence, which means that things succeed because of repeated thinking, but they can be destroyed in randomness without thinking.
Throughout the ages, many people who have achieved their careers are due to diligence and lack of fun; What I did was thought, but it was destroyed. How many historical allusions illustrate this truth.
To put it simply, these two sentences need three provinces.