Mr. Stulberg writes about excellence and mental health and is the author, most recently, of “The Practice of Groundedness.”

A few years ago, when I lived in Northern California, I often hiked under old-growth redwoods. The roots of these mammoth trees, stretching some 200 feet into the air above us, run only six to 12 feet deep. Instead of growing down, they grow out, extending dozens of feet to each side, enmeshing themselves with the roots of their neighbors. This is why we never see a lone redwood: They can survive only in a grove, bound together in obligation.

Humans, too, need one another: We are stronger and more robust when enmeshed with others in community. But in our age of autonomy, efficiency, boundaries and self-care, we too often deprioritize, if not overlook altogether, the wellspring of strength and meaning that comes from obligation.