Although Zheng Da considers himself a low-key master, compared to a true master, he still has obvious shortcomings.
His language is extremely limited.
You could see this from when Zheng Da went to Yunzhong Restaurant to guide Qin Huai early on.
His language basically consisted of: Do you get this? I'm talking about this, not that. The key to this is this, it's this feeling, yes, yes, yes, it's this, not that.
A purely encrypted conversation.
This time, even though Zheng Da was well-prepared, he still didn't overcome the language barrier.
Zheng Da chose not to overcome it and simply gave up.
As long as there's no language in teaching, there's no hurdle to overcome!
Using language to teach is something a master like Huang Shengli, who hasn't taught geniuses before, would do. Zheng Da believes geniuses like him don't need language; demonstrating directly is enough.
Zheng Da prepared thoroughly.
