The speaker looks at someone close to them, probably an older or ailing person, judging by the title and the limping, and tries to make sense of who they were. The first two stanzas describe this person from outside: someone who gets up each day just to keep things in place, who greets people and forgets them almost at once, and who keeps what matters in a murmur. Even the mirror seems to show them nothing, as if they had stopped looking for themselves.
The last stanza turns personal. "For me" marks a shift from observation to memory. The speaker will always picture this figure limping through an airport, or standing behind a neighbors' parade, trying and failing to say goodbye. Both images show someone at the edge of a crowd, unable to be heard.
The mood is quiet, tender and sad. Nothing is shouted, and the feeling comes through small gestures. The poem suggests love mixed with regret over a goodbye that never quite happened.