When a person has accumulated enough knowledge, they no longer need to prepare for their lessons.
This was another encounter with a professor-level instructor for Li Zheng since Zhou Chenghuan and Jie Qifen.
However, Du Songtao was more pragmatic than Zhou Chenghuan and more brutal than Jie Qifen, essentially digesting and condensing Stanford's courses and spewing them out like spores.
His knowledge structure was virtually flawless and he always managed to pinpoint issues directly and guide groups quickly to find solutions.
If Li Zheng's classes involved methodically demonstrating a full set of martial arts moves, then Du Songtao was about delivering the essence tailored specifically for each person in the shortest time.
According to Du Songtao, such a training course could only achieve quick results; there was simply no time to work on knowledge structure, which had to be naturally accumulated through subsequent work, a directional error on Li Zheng's part.