Once, long ago, when faced with the question of a cup, or what is the essence of "cup," I struggled with thought. Quickly I came to my senses and realized that I was not myself a cup. So, I found a cup and asked what its suchness was... It's response was to continue being a cup. In spite of whatever the billions had to say about what a cup truly is, it happily continued on its way.
Later, my curiosity took me back to the cup to inquire of its emptiness. To my surprise, it was the emptiness that answered me, thinking I was talking to itself, rather than the cup.
If this cup is empty, it said, then how is it I am filling it? To which I replied,
"If it's full of emptiness, how is it empty?" All this thinking made me thirsty, so I poured my tea, and suddenly I heard the emptiness exclaim: Alas, an empty cup!
So, I drank until it was again full.