The dream of owning their own piece of land is something that keeps both men going. In a period when men drifted alone from ranch to ranch, Lennie and George stand apart. First, they travel together and have each other as friends. Secondly, they have a dream of having something substantial that will make them less dependent on others and doing what others tell them to do. Unlike the men they work with, they have some kind of a goal, however remote that goal might be. George repeats the dream of the farm to please Lennie, but I also think the dream gives George hope that there is something better up ahead and that their life has some purpose.
According to critic Angela Hickey, Lennie represents that part in George that is childlike. It is this innocence of Lennie's that George patronizes by repeating their dream; however, it is Lennie's innocence also that allows George to entertain the possiblity of this dream. And, when Lennie dies, so does the dream.
The dream is what bonds the two men giving meaning to their lives and friendship; it is what keeps them from the terrible isolation that the other men experience. Without Lennie, George would probably have no purpose in his life. George tells another,
I seen the guys that go around on the ranch alone. That ain't no good. They don't have no fun. After a long time they get mean...you get used to going around with a guy
The repeating of the dream serves as a mantra. By saying it over and over again, George hopes to make it a reality. It is like a prayer to an uncaring God. The world around them declares over and over that they are nothing and will never achieve their dream, but the repetition of the prayer is the hope that somehow, someway, God will answer them. The fact that God answers a resounding "no" at the end with the death of Lennie makes the repetition of the prayer even more poignant.