It’s the first day of spring on the Appalachian Trail in Massachusetts when Bobby Zabarsky and his 20-pound pack round a bend and reach an inclined granite slab that is two stories high. The painted white blazes are unmistakable; the trail goes straight up. He stops, turns, and cracks a grin at his mother, who is following a few steps behind. “It’s a thing,” he says. “Yes, it’s a thing,” says his mother, Trish Whitehouse. “Better get going.” He rolls his eyes, then scrambles to the top. His score: 7 for grace and a perfect 10 for vigor. Bobby on the AT in Massachusetts. (Patricia Sisson)