Lennie and George share a dream of having a little farm. It would be a place they could call home, a place of belonging. This dream juxtaposes their itinerant life of loneliness and isolation.
O.K. Someday—we're gonna get the jack together and we're gonna have a little house and a couple of acres an' a cow and some pigs and—"
"An' live off the fatta the lan'," Lennie shouted. "An' have rabbits. Go on, George! Tell about what we're gonna have in the garden and about the rabbits in the cages and about the rain in the winter and the stove, and how thick the cream is on the milk like you can hardly cut it. Tell about that George."
"Why'n't you do it yourself? You know all of it."
"No…you tell it. It ain't the same if I tell it. Go on…George. How I get to tend the rabbits."
I think the dream gives them a sense of purpose and hope. It is something that brings George and Lennie together. It isn't so much as attaining the dream that keeps them going, it is the dream itself. The small farm is the American Dream that seems real but largely an illusion.