You can tear a poem apart to see what makes it technically tick, and say to yourself, when the works are laid out before you, the vowels, the consonants, the rhymes or rhythms, "Yes this is it. This is why the poem moves me so. It is because of the craftsmanship." But you're back again where you began. You're back with the mystery of having been moved by words.
Dylan Thomas, Welsh poet, short-story writer, and playwright, "Poetic Manifesto" in the Texas Quarterly, Winter 1961