Characters use the phrase throughout the novella, particularly when someone has been rambling or talking excessively. For example, when Crooks, the stable buck, is giving his opinion on the American dream, Slim interrupts him by saying, "You got your mouse, ain't you? I seen him. Go on and roll your hoop." In this instance, Slim is telling Crooks to stop pondering his dreams and focus on what he has at the moment.
The expression "roll your hoop" metaphorically suggests that a person should continue on their own path and not dwell on matters unnecessarily. It is similar to phrases such as "mind your own business" or "keep moving."
In Steinbeck's novel, the phrase serves to remind the characters to be present in their lives rather than getting caught up in dreams and aspirations that might be out of reach or unrealistic. It reflects the harsh realities of life during the Great Depression, where many people were struggling to survive and had little control over their circumstances.