Professor Jiang Kezhu stands in front of the students. (Photo: People's Daily)

84-year-old professor Jiang Kezhu of Zhejiang University gave his last lecture this month.

Jiang hurt his meniscus during a diving competition in his younger days. Students asked him to sit several times during the 3-hour lecture but he refused. “Teaching on one's feet is a basic requirement for a teacher,” Jiang said.

With trembling arms, he persevered in writing on the blackboard as in the past.

Professor Jiang Kezhu writes notes on the blackboard. (Photo: People's Daily)

He used to teach mechanical engineering. Every professor should leave his legacy of knowledge and experience to the students so that they can avoid the same mistakes, Jiang stressed.

He returned to the university in 1994 after his retirement until 2008. As time went by, Jiang always had an urge to teach the younger generation. Thus, in 2017, he returned to the university and delivered his last lecture on mechanical design.

He prepared a gravestone next to his wife's plot in the cemetery, the epitaph of which is, “I create, therefore I am; I teach, therefore I am; I think, therefore I am.”