If you were born like an ant, you should know that your life is thinner than paper, and you should not be higher than the sky. What do you mean, you and I are both cattle and horses?

This sentence is a metaphor, which roughly means that although life is as small as an ant, we should be self-aware and realize that our destiny is thinner than paper, and we should not have too high ambitions and expectations. Because Gankun (referring to heaven and earth) is doomed, we are all ordinary people like cattle and horses. This sentence expresses the helplessness to reality and resigned attitude.