There's a line from Tolstoy's diaries that always breaks my heart. "I was cleaning a room," he wrote, "and, meandering about, approached the divan and could not remember whether or not I had dusted it. . . . I could not remember and felt that it was impossible to remember—so that if I had dusted it and forgot—that is, had acted unconsciously, then it was the same as if I had not. . . . If the whole complex lives of many people go on unconsciously, then such lives are as if they had never been."

How often do we forget if we dusted something, or what we ate the night before, or the name of someone we met ten minutes ago? What percentage of our lives slips past unconsciously? Don't we owe it to ourselves to pay as much attention to the world as we can while we still have time?

In the Far North, I paddle an inflatable kayak over water so cold and still it is like gliding over lacquered ebony. I listen to ten-thousand-year-old iceberg chunks pop like frying oil when they are set into the pot atop the stove to become our drinking water. I get to know Sam Omik, a native of Pond Inlet, who, like a polar bear, eats primarily "country food" (raw seal and caribou meat), and who takes one taste of the tomato and fennel soup Philip serves us one afternoon and spits it onto the ice. Sam also has a half-million-dollar home in Iqaluit, two Ski-Doos, a wife who has published a book, and a deep fondness for cartoons.

As the hours slide past and the sun spins laps around the horizon, fear and displacement are replaced by something else: sublimity. When I left my wife planting lemon verbena in the gentle Idaho sunshine, I thought that I was leaving spring behind with her. But spring exists above the Arctic Circle too, once you learn to see it. Tiny willows creep across the ground of Bylot Island, wearing the fuzz of coming blooms. Some of them, an inch tall and no thicker than a pencil, are more than a century old. Dust blows down from beneath the retreating snows and creates melt pools on the ice as big as lakes.

Some of the photographers on the trip are disappointed that they didn't get better shots of narwhals. But I am exhilarated to have seen them. For how many more years, after all, will they come here and find cod?

"When I was a boy," Sam tells me one afternoon, "the glaciers on Bylot Island all reached the sea. Now they are a thousand feet back."

Another guide, Jason Aglak, adds, "In winter the sea ice would get five or six feet thick. Now it's rarely three or four."

On our last evening, during dessert, a bowhead whale shows himself along the floe edge not fifty feet from us. I watch his seemingly endless back pass through the field of my binoculars, and remember that they can live to be more than two hundred years old, perhaps the longest-lived mammals on earth. For how many springs has this same whale come to the floe edge to eat? What will happen to him if the ice goes away?

The skin of every whale—like the ice around camp, written over with tracks—is a record, each line a story. All told, I'm above the Arctic Circle for eight days—or one long day, depending on how you look at it. We make hot tea and laugh and eat hamburgers on a rim above a black, teeming universe, peering out at the ever-changing surface of the sea, each of us contemplating our own mysteries. We eat Triscuits in a snow squall. We brush our teeth in sweet, unadulterated sunlight at 2 a.m. We go for walks on Neptune.