Minor threatening to become major

"One of my fiction writer friends says that, in the process of working on a novel, his minor characters are always threatening to become major characters, and that his major character is always threatening to become a minor character. In other words, the process of storytelling is a seething, fermenting, somewhat unstable business. Such unwieldy shifts in proportion are also common, maybe even more common, in the making of poems--where a luminous image or statement can stage a coup d'etat at any moment, disrupting the apparent agenda of the poem; where any digression can become more interesting than the main thematic line. It is often hard to keep the poetry train on the tracks, and the willfulness of doing so is often death to a poem. Art requires strange collaborations between decisiveness and surrender." --Tony Hoagland