The speaker is a former rider, now alone and turned inward. "I touch nothing but myself" suggests a life with little contact, and the odd line about hands "rich in fur" hints at something half-animal, as if the speaker has drifted away from the human world, or perhaps that the hands remember the feel of horses' coats. Judging by the imagery, it could be either, and the poem leaves that open.
Then the past arrives in a dream, and the dream is full of horses. The sting comes in the last lines: the horses see the speaker as a "troll-like acquaintance," someone half-known and a little strange, not the partner they once carried. The speaker seems to see themselves through the animals' eyes and feels diminished, even faintly comic. The mood is quiet, wistful, and slightly eerie. There is loneliness here, but also a dry humor, as if the speaker accepts the change without making a fuss.