"I do not know whether I was then a man dreaming I was a butterfly, or whether I am now a butterfly dreaming I am a man"

The quote suggests that the line between truth and fantasy might be blurred. Zhuangzi is questioning whether the experiences we have in our dreams are any less real than our waking experiences. He raises the possibility that our presence might be absolutely nothing more than a dream, which it is impossible to ever truly know what is real and what is not.