A speaker steps out into the street, following the sun, and then makes an odd, striking comparison: they drink the way a scholar might at the burial of a book. The first lines feel open and easy, a simple movement from inside to outside, toward light. The second image turns more solemn and strange.
A book being buried suggests something finished or lost, perhaps an idea, a way of learning, or a stage of life. The scholar, someone devoted to books, drinks in mourning, or maybe in quiet release. The word "drink" also carries a double sense: the speaker might be taking in the sunlight and the street as much as any liquid.
The title, "Campaigner," adds a puzzle. A campaigner pushes for something, yet the speaker seems to wander. Judging by the imagery, the poem may suggest leaving the study behind and choosing lived experience over reading. The mood is quiet, wry, and a little elegiac, part grief and part freedom.