> "The best-laid schemes o' mice an' men / Gang aft agley."
This line means that even the most carefully made plans can go wrong, and it is a theme that runs throughout Steinbeck's novel.
The characters, George and Lennie, dream of a better life, but their plans are repeatedly thwarted by external forces and Lennie's own limitations. The title is therefore a powerful symbol of the fragility of dreams and the inevitability of misfortune.