The Chengyu (four Chinese characters used as an expression that conveys an entire story upon reading them) is read as zhuāng zhōu mèng dié, and means something like "Zhuangzi dreams [that he is a] butterfly." It's one of my favourite phrases and I want a tattoo of it eventually.

Basically, Zhuangzi is a Daoist philosopher from, uh, the Warring States Period (4th century BC). He wrote a work commonly referred to as just "Zhuangzi" and it's from that work that the phrase originates. The story goes thus (paraphrased): "Zhuangzi once dreamt that he was a butterfly and he was flitting around happily. He did not know that he was Zhuangzi. Then, suddenly, he woke up, and upon doing so realised that he was Zhuangzi again. However, he did not know whether he was Zhuangzi who had dreamt of being a butterfly, or whether he is a butterfly dreaming it was Zhuangzi."

I just really like things like that (The Matrix and Inception have similar premises and are two of my favourite plotlines). So I made a thing of it!