How does Of Mice and Men show that dreams help people stay hopeful about their lives?

The quest to fulfill dreams is an important theme in Of Mice and Men. Steinbeck develops the importance of dreams through the characters of George, Lennie and Candy. George dreams of having his own piece of land where he will be able to work for himself and not have to answer to a boss. He is conscious that he works hard yet has nothing to show for it. He tells Slim in chapter three,

The quest to fulfill dreams is an important theme in Of Mice and Men. Steinbeck develops the importance of dreams through the characters of George, Lennie and Candy. George dreams of having his own piece of land where he will be able to work for himself and not have to answer to a boss. He is conscious that he works hard yet has nothing to show for it. He tells Slim in chapter three,

"If I was bright, if I was even a little bit smart, I’d have my own little place, an’ I’d be bringin’ in my own crops, ‘stead of doin’ all the work and not getting what comes up outa the ground.”

This is George's dream and it keeps him hopeful that his life will one day change and he will gain the freedom which land will provide. Lennie shares George's dream but the simple-minded man focuses on only one aspect of the dream, to "tend rabbits." Lennie has an obsession with petting soft things so he is naturally intrigued by George's story about how they would raise alfalfa which would be fed to the rabbits. Whenever he gets a chance, Lennie begs George to tell the story of "how it's gonna be" when the two men go off to their own "little piece of land."

Candy too is overwhelmed by the dream. In chapter three, Candy's dog, who is old and decrepit, is shot by Carlson and Candy loses his best friend. For a time immediately following the shooting Candy is in deep depression until he overhears George tell Lennie about the land they hope to one day have. Candy offers to contribute $350 to the purchase and for a time it seems as though the dream may actually become a reality. Candy is positively giddy over the prospect of going with George and Lennie to "hoe in the garden even after I ain’t no good at it." George is also amazed that they might realize the longed for dream that had always seemed like an illusion. Steinbeck writes,

“We’ll do her,” he said. “We’ll fix up that little old place an’ we’ll go live there.” He sat down again. They all sat still, all bemused by the beauty of the thing, each mind was popped into the future when this lovely thing should come about.

The dream of the land keeps the men going. It's all they can think about and for a short time, Crooks is included, as the black man offers to also "come an' lend a hand." Unfortunately, Curley's wife threatens Crooks so he tells Candy he wouldn't want to go and was just kidding. Because he is black Crooks is ostracized and never able to realize his dreams. The other characters never realize the dream either, as the accidental killing of Curley's wife shatters the idea of the farm.