To build a folly is essentially to do something a second time, something at an inopportune moment. That something is always the memory of something forgotten, about which we can paradoxically say "There it is again."
Follies were misunderstood, purposeless constructions. They were often only small, extravagant gestures in a garden, easily whisking off the imagination to distant lands, a sort of time capsule built to awaken the memory and induce surprise in passers-by. They marked locations, organized secondary paths in a park, or simply predicted the arrival of better times—a demarcation, a sacred spot, a mysterious trail, a hill whose tragic rocky nature begged for a tower, a party, or the arrival of summer.
“It is demonstrably true that things cannot be other than as they are. For, everything having been made for a purpose, everything is necessarily for the best purpose.” — Professor Pangloss
Translation is always a treason, and as a Ming author observes, can at its best be only the reverse side of a brocade—all the threads are there, but not the subtlety of color or design. But, after all, what great doctrine is there which is easy to expound? The ancient sages never put their teachings in systematic form. They spoke in paradoxes, for they were afraid of uttering half-truths. They began by talking like fools and ended by making their hearers wise. Lau Tzu himself, with his quaint humor, says, "If people of inferior intelligence hear of the Tao, they laugh immensely. It would not be the Tao unless they laughed at it."