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
The garden is as central to the concept of an Islamic home as the hearth is to the European home. It is interesting, then, that the hearth-fire in old traditions has a similar association with the life of the inhabitants of the house.
Commonly, the fire of the hearth was not allowed to go out. It was carefully covered with ashes each night at curfew so that a few selected embers would survive until morning. (In fact, the word "curfew" originated from the French word for cover-the-fire—couvre-feu.) Raglan comments that "the alarm and horror felt if the hearth-fire went out are out of all proportion to the inconvenience caused" by the need to relight it.