What does it mean to "walk the world in the circle"?

It's just an adaptation of the phrase "heaven is round and earth is square". In ancient times, people believed that the sky was round and the earth was square. For example, the Qin dynasty standardized its currency by using round, square-hole money. Here this sentence has mastered the natural operation of the laws of heaven and earth, that is, the way of heaven, you can be in the heaven and earth without obstruction, there are elements of Taoist thinking in it.