Why is the brush important in 'Of Mice and Men'?

It's important because it's at the very beginning and the very end of the novel. The brush is a metaphor for how everyone in the great depression in America at that time went round in circles, doing the same thing every day. Having the brush at both ends of the novel shows the audience George and Lennie's dream is only a fantasy to keep them going, as they end up in the same place as they were at the beginning - they've made no progress.