The speaker begins with a simple habit: walking in order to think. Moving on foot is how they "see clear," and the phrase suggests that clarity comes from the body's rhythm as much as from the mind. The poem is spare and quiet, built from short lines that feel like steps taken one at a time.
Then the scene darkens. Night is "fitting" a "paper multitude," an image that is hard to pin down. It might be a crowd of pale, flimsy figures, or people made thin and unreal by the dark. Judging by the imagery, the speaker feels slightly set apart from them.
The last lines turn to a "mine back home / where I might have gone." That could mean a place of work, or a different life the speaker did not follow. Either way, the mood is reflective and a little wistful, with a sense of distance and a path not taken.