Learning Zen is a phenomenon of gold and dung. Before you understand it, it's like gold; after you understand it, it's like dung. (Zen Proverb)
Before you study Zen, a bowl is a bowl and tea is tea. While you are studying Zen, a bowl is no longer a bowl and tea is no longer tea. After you've studied Zen, a bowl is again a bowl and tea is tea. (Zen Proverb)