1. The stumbling block is the step forward. This sentence is a folk proverb without an author. It means that setbacks are inevitable experiences in life. If you dare to overcome setbacks, you will make progress and become more mature. 2. Sloth is the factory of poverty. If a person is lazy or careless, he will have no future and will eventually be poor. Therefore, it is said that laziness creates poverty. 3. The reason why people can do it is because they believe they can. The reason why a person can achieve something is because he has confidence in himself and believes that he can succeed. 4. The sparrow knows the ambition of the swan. From "Historical Records·Chen She Family", also see "Zhuangzi·Neipian·Xiaoyaoyou", it means how can a sparrow know the lofty ambitions of a swan, and is a metaphor for how ordinary people can know the ambitions of heroes.