The speaker pictures what will be left once they are gone, and the answer seems to be: very little. The poem begins with a list of ordinary things, thinking, cake, trouble, work, and says none of them will exist "in my absence." It's an odd mix. Cake is a small pleasure, trouble a burden, and the poem treats them all as equally cancelled.
Then comes the bluntest line: "No father or son." The speaker's family roles vanish too, which suggests that even the closest relationships depend on a living person to hold them up. The final lines, "A dead body, I hear, / is not much," are almost casual. The phrase "I hear" keeps the speaker at a distance, as if reporting gossip about their own death.
The mood is calm, dry, and a little eerie. There's no panic or grief, just a flat, matter-of-fact tone. That restraint makes the idea of nothingness hit harder, and it leaves a faint, wry humor hanging over something very bleak.