What a poem means is as much what it means to others as what it means to the author; and indeed, in the course of time a poet may become merely reader in respect to his own works, forgetting his original meaning.
Good poetry could not have been otherwise written than it is. The first time you hear it, it sounds rather as if copied out of some invisible tablet in the Eternal mind than as if arbitrarily composed by the poet.
Poetry, even that of the loftiest, and seemingly, that of the wildest odes, [has] a logic of its own as severe as that of science; and more difficult, because more subtle, more complex, and dependent on more and more fugitive causes. In the truly great poets... there is a reason assignable, not only for every word, but for the position of every word.
That is what all poets do: they talk to themselves out loud; and the world overhears them. But it's horribly lonely not to hear someone else talk sometimes.
We may climb into the thin and cold realm of pure geometry and lifeless science, or sink into that of sensation. Between these extremes is the equator of life, of thought, or spirit, or poetry,--a narrow belt.
And of poetry, the success is not attained when it lulls and satisfies, but when it astonishes and fires us with new endeavours after the unattainable.