The usefulness of a cup is in its emptiness

A learned man once went to a Zen master to inquire
about Zen. As the Zen master talked, the learned man
would frequently interrupted him with remarks like,
"Oh yes, we have that too....", etc.
Finally the Zen master stopped talking and began to
serve tea to the learned man; however, he kept on pour-
ing until the tea cup over flowed.
"Enough, no more can go into the cup!" the learned man
interrupted.
"Indeed I see," answered the Zen master. "If you do not
first empty your cup, how can you taste my cup of tea?"

The above was written by Bruce Lee in his Jee Kune Do manuscript. Use Google to locate the scanned pdf copy.

I can tell you personally that it is extremely difficult to "empty" one's cup in order to "taste" other's tea. Some years ago, I tried but failed to "empty" anything. Now I am trying it again and hope that I can empty 10-20% of "my cup of tea". BTW, I am relating this to IT skills that I know and don't know.

The moral of the story is "The usefulness of a cup is in its emptiness"