An empty cup!

This extract it's taken from a book called Zen Golf by Dr Joseph Parent:

A young man had read all the books he could find about Zen.  He heard about a great Zen master and requested an appointment to ask for teachings.  When they were seted the young man proceeded to tell the master everything he had understood from his readings, saying that Zen is about this and Zen is about that, and on and on.

After some time, the Master suggested they have tea.  He performed a traditional tea ceremony while the  student sat at attention, bowing when served, saying nothing.  The master began to pour tea into the students cup.  He poured until it was full, and kept pouring.  The tea ran over the edge of the cup and on to the table.  The master kept pouring as the tea ran off the table and onto the floor.  Finally, the student couldn't contain himself any longer, 'Stop!  Stop pouring!  The cup is full-no more will go in!'
The master stopped pouring and said, 'Just like this cup your mind is full of your own opinions and preconceptions.  How can you learn anything unless you first empty your cup?'

Is your cup empty?