Reading poetry requires both a great deal of effort and a great deal of stillness, which is probably one of the reasons so many people are afraid of it. It requires effort because there’s no easing into it. You must come to a poem ready to pay attention from the first word. And as you read, deciphering upended syntax and coping with the semantic shock of poetic juxtapositions and new images, you can’t really relax and enjoy it until you’ve worked through it. But it also requires stillness: you haven’t really read a poem until you’ve received its effect in a single impression. It reminds me of playing the piano. From inside a piece, as a pianist, you don’t really hear it properly until you’ve so thoroughly mastered it that you can let yourself play it while some other part of you, somehow, sits back and listens. Likewise the stillness of poetry is the stillness of a performance contemplated from within. What Nabokov said about books in general applies even better to poetry: you can only reread a poem.
The demands of poetry not only make it difficult, they make it dangerous.