The phrase "life is rolling in the world of mortals" expresses that life is full of variables and unknowns in this complicated and troubled world, just like marching in the rolling world of mortals. The profound meaning of this sentence is that life is impermanent and things are unpredictable. People can't predict which comes first, tomorrow or the accident. They should cherish the present, eat, drink and be merry in time, and don't wait until they lose it to know it is precious.
The phrase "Life rolls around in the world of mortals" comes from a poem named Song of Golden Zun, written by Prince Hongzhou, the fifth son of Yong Zhengdi in Qing Dynasty.