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
If we try to cross this lake by following only the stepping stones that lead toward our objective, we’ll soon get stuck. But what if we let go of our objectives? What if we focused on trying to find new stepping stones instead? This is novelty search. Instead of looking for something specific, you look for something new.
Novelty search isn’t just random, it’s chance plus memory. Together, these ingredients do something interesting.
...Stepping stones are also combinatorial. Each new stepping stone we discover expands our potential to find even more stepping stones. Collecting stepping stones is a luck maximization algorithm. By collecting and combining stepping stones, we might arrive at our destination by accident, or somewhere more interesting!