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
Another great dissertation from Mark Brown of Game Maker’s Toolkit: The Games that Designed Themselves. It’s the radical idea that designers should ignore their preconceived notions and look to the game itself to find out where the development should lead. How does something design itself? Well… the answer is: Prototypes.
A lot of great indie game masterpieces are the result of experimentation and early gameplay demos that changed the course of game’s development. As Brown points out, there’s a whole history of groundbreaking games that were developed “almost by accident” where bugs and glitches were turned into features.