Frank was 15 when he suffered his third bout of rheumatic fever. From his bed, he overheard the doctor tell his mother that his heart would never recover. "I don't know how long he'll live," the doctor said. For a child in 1939, that left little hope he would reach adulthood.

For some people, such a diagnosis is a death sentence. For others, it is a new lease on life. Frank didn't take long to make his choice. That June, be graduated from high school, the youngest in his class. He tried a succession of factory jobs. But as he pulled a lever and watched aftershave lotion fill one bottle, then another, then another, he thought, I can't do this the rest of my life. He enrolled in the only college in his hometown, which just happened to be one of the best engineering schools in the country.

A year later, bombs dropped on Pearl Harbor. Frank tried to enlist in the Army. When the recruiters wouldn't take him, he tried to join the Navy… then the Air Force… then the Coast Guard. The military doctors saw only his heart's weaknesses, not its strengths. Instead, after his graduation, he designed the engines for their submarines and jets.

Frank survived to see his 24th birthday, but his parents did not. Both died in their 50s. The youngest of Frank's two brothers, then 12, chose to live with his big brother. They subsisted on takeout food from the restaurant around the corner, sometimes ate pound cake and water for breakfast. Their two sisters, already married, and one sister-in-law kept the dust from getting higher than the books that littered the floor and held up the broken bed.

On workdays Frank had to drag himself out of bed. But on the weekends he was up and out by sunrise, exploring the East Coast and Canada by train, by borrowed car, by whatever rusted jalopy he then owned. His young brother was his usual traveling companion. Who else would dare share Frank's uncertain life?

Then just before Frank turned 30, his best friend's fiancée introduced him to her cousin. They had a second date, then a third, then he told her about his heart. After two months, he brought her to his doctor to explain what the future might hold. She already knew. She told him, "I'd rather be with you for a few years than with anyone else for the rest of my life."

Not long before the wedding, Frank begged his future mother-in-law to let him take his fiancée on an overnight trip. She thought he was crazy; "Just wait until you're married - you'll settle down."

Even after a three-week honeymoon, Frank showed no sign of settling for anything. He filled his spare time with whatever would challenge his spirit, enrich his mind and open his heart. He brought his new wife, who had rarely left her hometown, to the historical sites, art museums, planetariums he enjoyed. One day, he began building his own boat - a17-foot cabin cruiser - in their bathroom. He ran hot water in the shower until the steam made the wooden planks pliable enough to bend for the hull. His mother-in-law still thought he was crazy: "Just wait until you have children - you'll settle down."

On the Saturday before his first child was born, he took his very pregnant wife on a drive through the mountains. By the next Saturday, the infant was in the car's backseat, on her first visit to the beach. At 32, Frank was finally starting a family.

And nothing kept him from them. One snowy Christmas, as his wife was recovering from a miscarriage, Frank suddenly appeared in her hospital doorway. She was astonished. "How did you get here?" The blizzard had closed the local roads, and they lived four towns away. He was surprised by her question. "I drove as far as I could, then walked," he said matter-of-factly. It had never occurred to him not to be by her side.

Two Christmases later, she delivered a baby boy. Frank was nearly 40, against all odds. The adventures continued-some aimless, some with a purpose. An afternoon might be spent at the local airport, watching planes come and go from all over the world; or on ferry boats, riding back and forth between the same two piers. A glass milk bottle inspired a trip to the dairy farm where it was produced. A craving for lobster led to a drive to Maine nine hours away, returning the same day.

Most of his family thought he was crazy, too, to brave downpours and snowstorms to show up for special, or even an ordinary, occasion. But what better reason was there? When his youngest brother moved to Ohio, Frank borrowed a car comfortable enough for a 12-hour drive with his two young children and a wife eight months pregnant. They arrive in time for dinner and left after breakfast the next day so he could be at work Monday morning.

At 44, after his second daughter was born, Frank moved his family to the seashore he loved. Only a year before, he had sold the boat that had taken him 10 years to build, without ever seeing it in the water. (Wooden boats took too much time to maintain, he'd said. Let someone else spend his Saturdays scraping off the barnacles.) Now in his new backyard was a 21-foot fiberglass boat. Most weekends, Frank filled it with family and zipped back and forth from bay to ocean, dropping anchor just long enough to go fishing.

Though he now stuck closer to home, Frank still had unfinished business elsewhere. Over the years, he had made many visits to Washington, D.C., but somehow he had always missed one sight. He stopped there again in 1971 on the way home from a family vacation, and was rewarded at last: "We finally saw the cherry blossoms in bloom!" It seemed he had willed the trees along the Potomac to open their petals despite the April chill. Two weeks later, his heart, 47 years old and weakened by another illness, gave out.

I was 15 when Frank, my father, died. Not long before, he had kept me out of school to attend the funeral of his favorite aunt. As we left the church, one of his sisters chided him for wearing a sport coat. She tugged on his red tie. "At least you could have worn black."

"But this matches my jacket," he kidded her, pointing to the gray and maroon checked fabric. Out of her hearing, he told me, "A black tie won't bring Aunt Elizabeth back. And she wouldn't have cared what I wore. What mattered were the laughs we had sitting around her kitchen table."

I miss my father every day. My grief has made me intolerant sometimes. I am impatient with people who waste time, lay blame, complain about the size of their thighs. But life is too short for intolerance, too. A life is best measured not in years, but in joys, aimless adventures, laughter in the kitchen and gathering with those you love no matter what. Most of all, as both my parents taught me, it should be shared with someone you can't live without, though you may have to someday.

Eight years ago my husband and I moved to the same mountains where my mother almost gave birth to me four decades ago. On the days that I must travel into the city to work, my route takes me past the dairy farm I toured as a child. Other days, I drive however far it takes to see, even for a moment, those people I miss. Once in a while, I sneak off and go fishing. And you know, some people think I'm crazy.

None of us really know how long we'll live. But we all know how we can live. And that knowledge can change our lives.