The maze and the cheese
The book frames its story with a gathering of old school friends, one of whom tells a simple parable. Four characters live in a maze: two mice, Sniff and Scurry, and two little people, Hem and Haw. Each day they search the maze for cheese, which stands for whatever we want in life, such as a job, a relationship, money or health.
Eventually they all find a large supply of cheese at Cheese Station C. The mice keep their routine of checking it each day. Hem and Haw grow comfortable, build their lives around it and start to think of it as theirs.