(MONEY Magazine) – Retirement is a word that never furrowed the brow of pianist Arthur Rubinstein. Lobster, caviar and beautiful women probably should have, but Rubinstein nonetheless performed for two robust decades after his denunciation of moderate living before dying quietly in his sleep at 95. While not everyone expresses Rubinstein's bravado, all of us can share his zest in being active and purposeful all of his life. Today that resolve beckons a whole generation of Americans who are planning their retirements. Unlike previous generations, who saw retirement as the restful reward for a lifetime of travail, Americans entering the third quarter of life today are as likely to see retirement as a robust time of renewal and adventure. The purpose of this magazine, prepared by the editors of MONEY, is to help you achieve a great retirement and lifelong financial security. We will not beguile you with the notion that such goals will be easily achieved. To the contrary, they require discipline. Just as Americans have learned to make older bodies more physically fit than ever thought possible (the photo on the opposite page offers a stunning example), they are reshaping older minds as well. Here are the most important of those new realities: The senior boom. A baby born in America this year will turn 65 in a geriatric society: one in every five persons will be that age or older. This will be the inexorable result of major demographic changes that are unfolding all around us. The age seesaw of our population, once weighted by the young, will gradually tilt heavily toward the old. That is because of the reduction of childbearing, the maturing of the baby boomers and the extraordinary improvement in the life spans of Americans. Since 1965, life expectancy at birth has jumped from 70 to more than 75 today and could reach 80 by the year 2000. What does it mean? It means that extended families will no longer be primarily horizontal -- comprising brothers and sisters and cousins -- but will turn vertical: three and four generations of a single family will be alive at once. Already the average married couple in the U.S. has more living parents than children. It means that spouses will spend more years together after their children have left home than they did raising them. It means that the average woman today will spend more years caring for her aging mother than she will have spent caring for a child. Even more significantly, it means that whole new stages are being added to our life cycles. Once we were only young, middle-aged and old. Now there are bright new stops along the way. Take, for example, the young-old, an ebullient group stretching roughly from age 55 to 75. These are vigorous people who are moving from one career to another, or stepping aside for a semester or two of education, or experimenting with phased-in retirement, or raising venture capital for a company of their own. To them the idea of a quarter-century of R&R sounds ridiculous . . . and it is. The demand for long-term care. Families now stand a greater chance than ever before of having a disabled elderly relative to support. Those who do not prepare accordingly risk undermining the financial planning of two or even three generations. Given increased longevity, more and more parents are likely to have children who themselves are over 65. As consultant Ken Dychtwald points out, 10% of the senior citizens in the U.S. have children who are also senior citizens. One-quarter of the aged need some type of long-term care -- and the age group that most often does, those over 85, is the fastest growing. The number of disabled elderly Americans is expected to more than double between 1985 and 2020. In the past, almost all of them would have been taken care of by families, frequently by a daughter in her mid-fifties. But the ability of families to care for the elderly is rapidly weakening. By 1990, more than 60% of women 45 to 54 are expected to be working. Indeed, the most reliable predictor of a disabled older person's chances of entering a nursing home is the absence of living children -- or their presence in the labor force. Unprecedented wealth. The generation now nearing or in retirement is the wealthiest in U.S. history. These are the people who bought houses cheap after World War II, prospered during the postwar economic boom, saw the value of their homes inflate during the 1970s and paid far less into pension plans and Social Security than they will take out. Much of their wealth is in real estate: nearly three-fourths of people over 65 own their own homes. Their task is to design financial plans that help build, protect and pass on this staggeringly large wealth to the next generation -- an event that will affect the retirement and estate planning of millions of individuals and families. ''For the first time, possibly, in human history,'' writes columnist Robert Kuttner, ''a large percentage of people will inherit substantial financial benefits from their parents.'' Unparalleled opportunities. The goal behind both the acquisition of family wealth and successful retirement planning is financial independence -- and the opportunity to make the most of it. More and more parents are living financially independent of their children, and not simply because of Social Security. Half of the couples retiring today have a pension from a public or private employer. That can give you remarkable freedom to decide just how much you want to work, and when, and where. You can yield to passions and causes that you may have put off for years, from travel adventures to a whole new world of post-graduate study. The time and the zest for both are making retirees the greatest wanderers and scholars of the age. Increasingly complex planning. The price of opportunity is complexity. Consequently, there are many steps you have to take to prepare for successful retirement. Moreover, success today is based on a lofty idea that used to be unthinkable: Americans want to provide for their families and then retire with no reduction in their standard of living. First, you have to decide when to retire. That sounds simple, but you could spend many bitter nights regretting the wrong decision. You have to worry about whether there will be enough money to live on until the end of your life and your spouse's. If you are to get a lump sum, you must suffer the tortures * of the damned over whether you'll invest it poorly and live out your fourth quarter as a burden to your children. Even if you invest your nest egg wisely, you must submit to the nightmare of all retirees: no matter how smart and provident you are, inflation wipes you out in the end. If you move too hastily to some putative paradise, you might wind up repenting your mistake at excruciating leisure. And you must wonder how you can expect to escape the paralyzing boredom that afflicts so many who no longer have jobs to go to. Fortunately, the survival strategies for the future are at hand. Those families that learn to talk to one another candidly about some sensitive topics -- Does Dad have a will? Shall we ask the children about moving? -- will thrive. So will people who see retirement as a glorious mixture of work, play and learning. Says MONEY senior editor Joseph Coyle, who directed the preparation of this issue: ''The third quarter of life can be a kind of second adolescence. Like the first one, it is fraught with exhilaration and fear of the unknown. The difference is that this time you are bringing wisdom with you, and the experience should be that much sweeter. You might say that people who manage it all right are at last coming to their senses. After the agonies of growing up and the terrible pressures of succeeding at both career and family life, you are about to come into your own.''