Who is Dream Man from Ficciones and what is their importance?

Dream Man appears in the story, The Circular Ruins, in which, he appears on the shores of a river and falls into a deep sleep at the foot of a circular ruins. While there, the Dream Man discovers that he enjoys sleep and decides to spend the majority of his time sleeping. At first, his dreams are vivid. Later, however, he begins to suffer from insomnia and is unable to dream.

When he is later able to dream again, he begins to dream of one person, who forms within his dreams until he is a complete man. He then teaches this one person, thinking of him as his son. Eventually, the Dream Man teaches his son to leave his dreams and get out in the world. At the end, the Dream Man is consumed by a fire that encroaches on the ruins, and although he isn't hurt, he comes to the conclusion that like his son, he is simply the product of another man's dream.