The title borrows a famous idea, that an unexamined life isn't worth living, but the poem seems to answer it with weariness. The speaker describes a question that hurts the way an old scar does: healed on the surface, still tender to the touch. Such a question, they say, belongs in a "good grave." It shouldn't be sent out as a "letter to hope," as if asking it might only bring more disappointment.
Then the poem turns. "Here lies the moon" echoes the language of a gravestone, so the moon seems to join the buried things. It is "great as a clock," large and steady, counting time while "telling pretty stories." Those stories sound comforting but not quite trustworthy.
The mood is quiet, wry, and a little sad. The speaker seems tempted to let hard questions rest and settle for beautiful distractions, yet the poem's own careful looking suggests that the questions haven't fully gone away.