Empty your cup

My husband used to teach Tae Kwon Do, I recall a story I heard him tell some students having a hard time with some new techniques. The story was passed down to him from his master and his master before him I believe it originated in a book. It goes something like this.

A skeptical man once came to a master to learn his art, the man could not seem to master the techniques of the master whatever he tried. He would then tell the master that it wasn't possible to learn these techniques and would have a list of reasons why. At some point the patient master called his student to meet him for some tea. The man joined him and sat down for tea. His master started to pour his tea and when the cup bacame full and started to spill out onto the tray he continued to pour...The student said to him Why are you still pouring the tea? Can't you see the cup is full and the tea is just spilling out? His master said You are like this cup. The student didn't understand and asked what do you mean? The master said Whenever I teach you a technique you tell me all the reasons it is not possible. You are so full of information you can't hold anymore. so like the cup when I try to give you something new it just spills out on the floor because there is no more room for it. If you want to master these techniques you must first empty your cup or nothing new will fit.

Please forgive me if the story is not exactly right but I believe the point does come across here. If we are going to achieve a perfect existence we must empty our cup.