The poem sketches a portrait of a man whose gift for sensing the world has become a burden. As a boy he was small, underfed, and defensive, fighting back with guerrilla tactics. As an adult he is tall, strong, and neatly presentable, running a business that makes ink and paper. His clients judge him by his products, not by who he is.
The real subject is his inner life. The speaker compares his mind to a handmade violin, delicate and always resonating. He picks up the feel of a person or a group instantly, and those feelings are so strong that he withdraws. The "ugly noises" he hears suggest that he takes in more than he can handle.
The mood is tender but weary. Work crushes him "like tongs," and life hurts. The ending offers a quiet relief: he gets through each day because of his wife's embrace.