Why is Yuan Lefan's son short-lived?

The reasons for Yuan Lefan's son's short life are as follows:

Let's look at the fate of Yuan Lefan's son Yan Yuan. Yan Yuan was a scholar at the age of 44 and died at the age of 46. He is a short-lived man. In Four Disciples from Fan, he said to his son, "Your life is unknown", and it is indeed "your life is unknown", because life is poor, and it is better to know than not to know!

Want to know what Yan Yuan's identity is, but that's the first scholar of Fan Fan Four Schools, who was entrusted by Yuan Lefan to study Fan Fan Four Schools. Yan Yuan's Farewell under the temptation, which is the realistic version of Farewell under the temptation and the original version of Farewell under the temptation, why is the effect so poor? Is the "Four Disciplines" impairing Yan Yuan's life span or is it useless at all?

The four disciplines are introduced:

In the Ming Dynasty's "Leaving Fan under the temptation", I heard Zen master Yungu say that doing good deeds can change my fate, so I worked hard with my wife to do all kinds of good deeds. There are more and more good deeds, and the unfortunate fate of the couple calculated by the fortune teller has turned into a better life: the fortune teller said that he would not live beyond 53 years old, and as a result, he was still writing "Four Commandments for Fanfan" at the age of 70, saying that he had no children all his life, and as a result, he gave birth to two sons in middle age. Fan Fan's Four Commandments is a family instruction written by Yuan Lefan to his two sons.