Because it's the most direct way to express your desires.

因为这是最直接地表达你的愿望的一种方式。

I want to 课堂 - SpeakingMax英语口语达人

Its direct relationship with the thing that's most closely adjacent to it somehow either through similarity or dissimilarity can never be a relationship of identity.

符号和实物之间的关系,即使是最接近的事物,是通过相似处和不同处建立的,但是这不是一种永恒的关系。

耶鲁公开课 - 文学理论导论课程节选