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
I must come to the topic of “selling” new ideas. You must master three things to do this:
Giving formal presentations,
Producing written reports, and
Mastering the art of informal presentations as they happen to occur.
All three are essential—you must learn to sell your ideas, not by propaganda, but by force of clear presentation. I am sorry to have to point this out; many scientists and others think good ideas will win out automatically and need not be carefully presented. They are wrong; many a good idea has had to be rediscovered because it was not well presented the first time, years before!