From this part, we know that things changed. Both the mice's and the littlepeople's cheese has run out. But they acted differently. The mice accepted the fact and were quickly off in search of new cheese. The two littlepeople, however, couldn't believe it and refused to face it. They spent a lot of time thinking why this sort of thing happened to them instead of moving on to find new cheese.
Most of the time, I used to be like the littlepeople. When facing changes, I felt nervous or sad and couldn't know what to do. Everything real is rational. I will take every change that will happen to me for granted and accept them as challenge or chance.