Somewhere in our brains we carry a map of our relationships. It is our mother’s lap, our best friend’s holding hand, our lover’s embrace — all these we carry within ourselves when we are alone. Just knowing that these are there to hold us if we fall gives us a sense of peace. “Cradled,” “rooted,” “connected” are words we use to describe the feeling that comes of this knowledge; social psychologists call this sense embeddedness. The opposite is perhaps a more familiar term — we call it loneliness.