Dreaming of reality, reality of dreaming

"Once I, Chuang Tzu, dreamt that I was a butterfly, a butterfly flying about, feeling that it was enjoying itself. It did not know that it was Chuang. Suddenly I awoke and was myself again, the veritable Chuang. I do not know whether it was Chuang dreaming that he was a butterfly or whether I am now a butterfly dreaming that it is Chuang." -- Chuang Tzu, Taoist philosopher