Here’s the view of the Wood Nymph Butterfly the first time that you ever see one. You’re probably on a trail that skirts the edge of a wooded habitat.
Two possibilities present themselves. Cercyonis pegala will 1) will flee, flying low and disappearing into dense tree undergrowth or into the field vegetation or 2) it will allow you to continue your approach and then flee.
We can presume that this one is a female. Females perch. Males patrol, searching for receptive females. When you first become fascinated with butterflies, the non-stop, seemingly senseless flight of male Wood Nymphs justifies your thinking that these butterflies are ‘crazy.’
So here again is a butterfly species that almost seems to be trailing/tracking you as you happily hike that trail along forest’s edge. This is the kind of escort that is appreciated as I spend hours working unspoiled habitat, on the hunt for butterflies to photograph. I see Wood Nymphs, but I don’t see humans for hours on end. I sometimes stop, look skyward and think.