"The Japanese Quince" by John Galsworthy, is a short story about a man who seems to be experiencing a total disconnect from the world outside his home. The plot seems fairly straightforward.
Quite to his surprise one day, Mr. Nilson—a man "well known in the city"—feels very unusual as he looks out of the window, and he is not sure what the cause might be. He goes out for a walk, and he experiences a "feeling of emptiness," a "queer sensation," a "faint aching just above the heart," and a "choky feeling in his throat." While Nilson feels that he looks healthy, it is suggested that these minor maladies reflect Mr. Nilson failure to appreciate the physical world around him. He is so distanced from nature, that the birds singing and the Japanese quince tree—even meeting his neighbor— throw him off base.
Nilson does not recognize his confusion in connection with other things going on around him. He speaks stiltedly to his neighbor, Mr. Tandram, who seems rather nervous to be speaking to Nilson. The author infers that Nilson (and perhaps Tandrum—who seems to be feeling the same as Nilson) has a "hole in his heart." Figuratively, this means that there is something lacking in his character: he doesn't not connect with others and he is so far removed from the physical world that experiencing any pleasure in it makes him believe he may be unwell.
Then, in a moment of clarity, Nilson sees the other man as an exact caricature of himself.
...in a moment of self-recognition, [Nilson] regards Mr. Tandram as appearing a little foolish, "as if he had seen himself..."
Quickly Nilson goes inside to get away from the world at large, hiding in his house, and later (we can expect) in the city where he spends his time. He is no closer to understanding what nature and his body are trying to tell him: that life is waiting to be embraced—just outside his door.