Why is the dream recited repeatedly?

The dream of having a little farm is recited so many times because it keeps Lennie and George focussed. Lennie needs the reassurance that a child might need that the future will get better. George needs to recite it to retain his sanity as they move from farm to farm. The dream is all they can hold onto.

"I remember about the rabbits, George."

"The hell with the rabbits. That's all you can ever remember is them rabbits." pg 18