The poem begins like an ordinary errand. Someone asks what's needed from the store, and the answer is a normal grocery list: milk, eggs. Then "Birth Control" slips in as if it belonged with the rest, as casual as a carton of eggs. The list is repeated word for word, which makes it feel like a chant or an echo, as though the question and the items keep circling in the speaker's head.
The last line changes everything. "I never buy any of those things" is flat and plain, and it leaves a lot unsaid. Judging by the text, the speaker may be cut off from the ordinary routines the list suggests, or may simply feel apart from them. We aren't told why. The mood is quiet, a little lonely, and unsettled. The humor of an everyday list gives way to distance, and the poem trusts the gap between what is asked and what the speaker admits to carry the feeling.