Hi Richard,
Nai Yin (奈因), a Japanese Zen master during Ming Zhi (明治) era, received a university professor who came to inquire about Zen (禪). When Nai Yin served tea, the professor kept talking about his idea on Zen. Nai Yin poured his visitor's cup full, and then kept on pouring.
The professor watched the cup overflow until he no longer could restrain himself, "It is full! No more will go in!"
"Like this cup," Nai Yin said, "you are full of your own opinions and speculations. How can I show you Zen unless you first empty your cup?"
Richard, to learn, one needs an open mind and a humble heart (虛心). Listen and think carefully what others say. Don't prematurely conclude and believe that you have known everything.
With love, Patrick