John Steinbeck's Of Mice and Men is intended to show the hard lives of the masses of uneducated, unskilled men who have to labor in the California fields for low wages, spartan accommodations, and bad food. George and Lennie are fictional characters who are intended to represent all the others. Like many other itinerant farm workers, they dream of having their own little piece of land so that they could escape from their lives of misery, insecurity and fear. These bindlestiffs tramp the roads looking for work, but they can't be sure of finding any. And if they don't find a place to give them shelter and food, they can starve to death along the roadside and nobody would care.
Call for the robin-redbreast and the wren,
Since o'er shady groves they hover
And with leaves and flowers do cover
The friendless bodies of unburied men.
Call unto his funeral dole
The ant, the field mouse, and the mole
To rear him hillocks that shall keep him warm
And (when gay tombs are robb'd) sustain no harm;
But keep the wolf far thence, that's foe to men,
For with his nails he'll dig them up again.
Steinbeck created two characters to represent these hordes of hopelesss bindlestiffs rather than one. The author did this for a practical purpose. He called his book "a playable novel." He intended to convert it into a stage play immediately. Both the book and the play came out in 1937. In the book most of the exposition is conveyed through dialogue, because that would make it easy to convert the book to the stage play. But for dialogue, of course, Steinbeck needed two characters who would be talking to each other. There is a great deal of verbal explaining done in the book which would ordinarily be presented in straightforward prose exposition. (The Weed incident is a good example.) The book reads like a play. All the characters do a lot of talking to each other, while at the same time characterizing themselves and others, and also conveying information to the reader and the future theater audience.
Steinbeck hit on the idea of making one of his main characters mentally handicapped. This requires the other character, George, to be explaining things to Lennie all the time, including George's plan to escape from their poverty and insecurity by getting a few acres of land with a little house on it. In creating Lennie, Steinbeck created the most memorable character in his story. People will always remember Of Mice and Men by remembering Lennie. Their joint motivation drives the story. But, as the title suggests,
But Mousie, thou are no thy-lane,
In proving foresight may be vain:
The best laid schemes o' Mice an' Men,
Gang aft agley,
An' lea'e us nought but grief an' pain,
For promis'd joy!
George and Lennie's dream is so important to them because its fulfillment would have meant so many things. It would have meant security and freedom. It would have meant survival without having to struggle with other desperate men for a bunk and having to fight with strangers over the last scraps of food on the platters. It would have meant rest and an end to all that tramping up and down the enormous state of California. It would have meant a real home.