At age 38, with a toddler son and a thickening waistline, Katherine May makes the decision to hike the 630-mile South West Coast Path in England, a rugged trail that "clings as close to this island's crinkled edge as possible; so close, in fact, that chunks of it regularly fall into the sea." She will hike in stages, she decides, sometimes alone, sometimes with a friend. She will finish before she is 40.

In "The Electricity of Every Living Thing" (Melville House), May writes about her journey in vivid, exuberant prose — the trail leaves her "wild with wonder," the sky is full of birds she wishes she could identify, the "nothingness of the sea" fills some need deep inside of her. She's always been different, she knows, overly sensitive to light, noise, touch and smell. So much of her energy is expended trying to fit in, trying, to "pass" as a normal person.

But it isn't until she's driving to the trailhead during a blinding rainstorm that she realizes what it is that makes her different. A radio interview with a woman with Asperger's Syndrome sets off a burst of recognition in her own brain. This explains everything.

"I don't want a cure for being myself," she says. But "I need to know what I am."

In this memoir, the author of "Wintering" examines her life, her self, her choices, as the journey along the coast becomes a reckoning. Even as the hikes become "less of a leisure activity and more of a grueling contest against my own soul," she presses on. Walking "is the only place where I don't have to pass."