The speaker is trying to numb themselves. Overwhelmed by doubts about whether anything they do matters, they imagine buying a double-sided magnet that will push their thoughts and feelings away. The poem moves between big, anxious questions (am I just a speck of dust if I die anyway?) and small, almost desperate bargains: moving a grain of sand must make them important, and they admit they cannot kill their own pride. They also seem caught between rejecting roles and needing them, wanting a number, a family, a label to tell them who they are.
The mood is bleak, restless and a little bitter, with flashes of frustration, like gripping their hair out. In the last section the numbing seems to work. Feelings are set to "thirty-two below," the heart's ice spreads, and emotions become candles to be blown out. The ending feels more like exhausted relief than peace, since the "aches of my soul" are still there in the final line.