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
There are two classes of problems caused by new technology. Class 1 problems are due to it not working perfectly. Class 2 problems are due to it working perfectly.
...Class 1 problems arise early and they are easy to imagine. Usually market forces will solve them. You could say, most Class 1 problems are solved along the way as they rush to become Class 2 problems. Class 2 problems are much harder to solve because they require more than just the invisible hand of the market to overcome them.
...Class 1 problems are caused by technology that is not perfect, and are solved by the marketplace. Class 2 problems are caused by technology that is perfect, and must be solved by extra-market forces such as cultural norms, regulation, and social imagination.