The first line is the DNA of the poem; the rest of the poem is constructed out of that first line. A lot of it has to do with tone because tone is the key signature for the poem. The basis of trust for a reader used to be meter and end-rhyme.
Billy CollinsYou know how sometimes you just have a memory of looking up and seeing a face looking over your crib and then remember nothing until tenth grade? - I have one of these early memories where I'm in the back of my parents' car, a place I loved to spend a lot of time as an only child, not having to fight with venomous siblings over the only toy.
Billy CollinsA sentence starts out like a lone traveler heading into a blizzard at midnight, tilting into the wind, one arm shielding his face, the tails of his thin coat flapping behind him.
Billy Collins