When Marcher encounters May in Chapter 1, he can barely remember their first meeting in Naples 10 years prior. Wishing for some kind of romantic or critical rapport with May, he imagines a "sketch of a fresh start" with her:
He would have liked to invent something, get her to make-believe with him that some passage of a romantic or critical kind had originally occurred. He was really almost reaching out in imagination—as against time—for something that would do, and saying to himself that if it didn’t come this sketch of a fresh start would show for quite awkwardly bungled.
The metaphor here is a "sketch of a fresh start." In this scene, Marcher feels guilty because he does not remember much about May. He bungles every attempt to recall where they first met and exactly what proceeded, and May must gently correct him about the particulars. Embarrassed, he imagines trying to get her to "make-believe with him" that something romantic had happened, and he uses the metaphor of a "sketch" to describe a possible method of convincing her, and himself, that their relationship is of some social significance.
This metaphor characterizes Marcher as a very passive character. Throughout the story, he remains a hesitant participant in his own life, and he imagines or "sketches" out possibilities without ever enacting them. He has the potential to be the creator of his own life, but he gets stuck on the metaphorical drawing board. Another example arises when Marcher fearfully imagines future possibilities for "the beast" (his fate) but never takes action to achieve anything or to prevent his life from slipping away from him. The scene in which he imagines sketching a fresh start shows him doing with the past what he then does with the future: absolutely nothing.
In Chapter 2, Marcher uses the metaphor of buried treasure to describe his sudden good fortune in rediscovering through May his own feelings about fate:
[...] for our gentleman this was marked, quite as marked as that the fortunate cause of it was just the buried treasure of her knowledge. He had with his own hands dug up this little hoard, brought to light—that is to within reach of the dim day constituted by their discretions and privacies—the object of value the hiding-place of which he had, after putting it into the ground himself, so strangely, so long forgotten.
Here, the narrator refers to the memory of Marcher's fate as "the buried treasure of [May's] knowledge." Figuratively speaking, Marcher has "dug up this little hoard" and "brought to light" an object of great value that he had once put "into the ground." This metaphor shows how much Marcher values his ideas about destiny. He later discovers that his fate is simply to wait for his own fate. However, having rediscovered his own fate through May's eyes, and being encouraged by her kindness to await it, he begins to see so much value in it that he spends his whole life wondering what it will be.
In the end, this so-called "treasure" turns out to be nothing but a false prediction of greatness. Marcher makes no move to achieve anything in life, waiting for his fate as May dies and the hoard he dug up dwindles away to nothingness. The metaphor of buried treasure serves as a reminder that all that glitters is not gold, and that memories or predictions have no inherent value. The true value in life, the book seems to suggest, comes from taking action and living one's life without worrying too much about what will happen next.
Throughout the story, John Marcher maintains a singular focus on awaiting his fate. However, when he discovers that his fate has been to wait for nothing, he begins to think of his own passive stupidity in terms of metaphorical blindness. In Chapter 6, the narrator says:
The name on the table smote him as the passage of his neighbour had done, and what it said to him, full in the face, was that she was what he had missed. This was the awful thought, the answer to all the past, the vision at the dread clearness of which he turned as cold as the stone beneath him. Everything fell together, confessed, explained, overwhelmed; leaving him most of all stupefied at the blindness he had cherished.
The metaphor here is "the blindness he had cherished." In this passage, Marcher has just visited May's grave and realized that "she was what he had missed." Much to his horror and sorrow, Marcher missed out on the opportunity to have a relationship with May. His single-minded vision of discovering his own fate had made him selfish, stupid, and unaffected by May's love for him. Despite her habitual hint-dropping, he fails to discover the truth until it is too late. After he views her grave, he is "stupefied" at his own blindness to her love. While he, of course, wasn't wasn't literally blind, he lacked knowledge or insight to realize that he must take action and shape his life in the way that suited him. He was also oblivious to May's advances. Requiting her love would have saved him, but she passes away before he can make a move. The metaphor of blindness thus serves to demonstrate how deeply ignorant Marcher remains throughout the story.