The poem, as it starts to form in the writer’s mind, and on paper, can’t abide interruption. I don’t mean it won’t but that it can’t. When writing, as nearly as is imaginatively possible (and that is very near indeed), one is undertaking the action, or has become the character (think of what Keats said), in the unfolding scene or action of the poem. To interrupt the writer from the line of thought is to wake the dreamer from the dream. The dreamer cannot enter that dream, precisely as it was unfolding, ever again because the line of thought is more than that: it is a line of feeling as well. Until interruption occurs, this feeling is as real as the desk on which the poet is working. For the poem is not nailed together, or formed from one logical point to another, which might be retrievable—it is created, through work in which the interweavings of craft, thought, and feeling are intricate, mysterious, and altogether “mortal.” Interrupt—and the whole structure can collapse. An interruption into the writing of a poem is as severe as any break into a passionate run of feeling. The story of Coleridge dreaming his way through Kubla Khan until the visitor from Porlock rapped upon his door is equally understandable whether Coleridge was actually asleep dreaming a dream, or dreaming-working. The effect is the same.
–Mary Oliver, A Poetry Handbook, pg 117