We could build the finest house on the planet, maybe design it along the lines of some form of Frank Lloyd Wright architecture, but without an opening to get in, it would serve little purpose to us. The Dao tells us that we can make a beautiful vase, but without the emptiness within, it would not be useful, at least as a vase. The purported teachers have prattled on about what emptiness is for thousands of years in all kinds of philosophies. Just remember this, without emptiness, your cup of tea can’t accept anymore. Drink your tea.