I believe it was the 19th-century political thinker Alexis de Tocqueville who observed in his "Democracy in America" that the United States was protected/defended by two great oceans. Others might invade, but there were a couple of mighty obstacles in their path.
From the 3rd century BC until the 17th century, the Chinese erected the Great Wall of China as a means of keeping Mongol, Turkic and other nomadic tribes at bay. By any estimate, the wall is a monument to the desire for stability and peace.
And in a human life span, there is ample evidence that individuals erect their own ramparts and moats in an effort to keep bad fortune -- or disruption of good fortune -- at arm's length.
An interesting aspect of the defenses of this life is that at the same time they may keep enemies at bay, they also restrain and confine those who have built them. And those confines and restraints and limitations can become galling, if not horrifying, over time.
Just thinking that a little careful investigation of a sense of safety and certainty is worth the price of admission. To what extent do the chosen limitations express the limitless ease -- or happiness, if you prefer -- that each is capable of? If keeping things at bay is the price of peace, how nourishing could such a peace possibly be?
Just something to consider, I think.