Regarding his knowledge on technical stuff, he said, in Chinese, in his interview:
"Don't ask me about cameras, I don't know them. I rely on my assistant for that."
in another interview, he said camera is just a tool.
In one of his English interviews, he said many youngsters don't understand color theory.
I think color theory is his strong technical knowledge.
He shot HERO and IN THE MOOD FOR LOVE, he is really something, even if he appears like a half drunk mad man.