This is a portion of the Canada Cliffs Trail near Echo Lake in Acadia. It’s a good example of some of the technical (challenging) terrain we encountered while hiking in Acadia.
It is nice to have smooth paths to walk (or run) on and most of the trails we use near our home are fairly smooth. But just as walking on flat ground doesn’t do much to prepare you for hills, walking on smooth ground doesn’t do much to prepare for technical trails.
It is not much of a stretch to say that life is filled with technical or challenging terrain. Nothing prepares you for challenges other than facing challenges.