Evocation joke

In ancient times, there stood a big stone tablet beside a grave, written by the cousin of the deceased. Passers-by all laughed. Its inscription is as follows:

My cousin is human. At the age of 30, the boy tried and failed Then abandon the text and fight. A feather was displayed on the martial arts field, and the officials were very angry and found it. He studied medicine in his later years, and he chose his own prescription to serve him.