Lennie loves to listen to George talk because George is able to express what Lennie feels but doesn't have the ability to put into words. In Chapter One, Lennie asks George to tell him the same little bit of philosophy he has told so many times before that it has become like a poem or a litany.
Steinbeck uses dialogue as exposition throughout this work. As in a play, what the characters say to each other is intended to convey information to the reader. It was Steinbeck's intention to convert the book into a stage play, and his heavy reliance on dialogue made the adaptation easy. The play was produced in New York in 1937, the same year the book was published. When George tells Lennie what he asks him to repeat, Steinbeck is using the dialogue to convey to the reader, and to the future theater audience, the main message of his story.
George's voice became deeper. He repeated his words rhythmically as though he had said them many times before. "Guys like us, that work on ranches, are the loneliest guys in the world. They got no family. They don't belong no place. They come to a ranch an' work up a stake and then they go inta town and blow their stake, and the first thing you know they're poundin' their tail off on some other ranch. They ain't got nothing to look ahead to."
Then in the final chapter, just before he kills Lennie, George repeats some of the words that his friend loves to hear.
George said, "Guys like us got no family. They make a little stake an' then they blow it in. They ain't got nobody in the worl' that gives a hoot in hell about 'em--"
The story begins and ends in the same place, partly to suggest that guys like George and Lennie are going nowhere. When George performs his mercy killing, it is as if he is saving him from a life that offers nothing but toil and pain. George will be lonelier than ever now without his best friend. Like the other guys who work on ranches, George "ain't got nothin' to look ahead to."