Like many of my peers, I had thought that I could gently start thinking about retirement in my mid-fifties. But as my mid-fifties arrived, and as the debate about the human lifespan rages on, I’ve been confronting a new question: what if I live to 100?

For more, I looked to a book by Lynda Gratton and Andrew Scott, two London Business School professors, called The 100 Year Life. Half the children born today, they say, have a 50% chance of living to 105. That’s up from only 1% a century ago.

We used to have a few simple phases to existence: childhood, education, work, and retirement. Now, entirely new phases of adulthood have emerged. My son, who is in his mid-20s, is pretty typical. After graduating from college, he moved abroad to work for a start-up, first in Haiti, now in Senegal. He is at the very beginning of his career: exploring the world, delaying any kind of emotional or physical settling down that, a generation ago, would have been the norm at his age. This whole decade is an entirely new phase, referred to as ”emerging adulthood,” and it’s something experts are suggesting may be a normal extension of learning and experimentation for a species living in an ever more complex world.

I am also experiencing an entirely new phase of adult development. Like my son, I’m exploring the world and have moved to a new country. I am recently remarried and developing ideas for new businesses. A generation ago, someone my age would have been gently slowing down, while I, and many of my cohort, feel like we’re at the very beginning of the second half of life. My children are grown and gone. I am as free as my son, with a bit more savings on the side.

Our decades strangely resemble each other – and have big implications for how individuals and companies may want to rethink a whole host of issues, from career management and pensions to mobility and leadership criteria.

For individuals, longer lives will mean that we are likely to reinvent ourselves many times over. We will want to learn to re-learn and be open to repetitive re-training. Lifelong learning will become an essential part of adult development.

Gratton and Scott also propose managing a range of assets that go well beyond the financial, although underfunded pensions will be a key challenge for almost everyone, everywhere. They group these into three areas and argue that over time, you want to review that you are investing enough to balance out your portfolio for a lifetime:

Productive assets: Knowledge, skills, professional social capital, reputation

Vitality assets: Health, relationships, love, regenerative friendships, balance

Transformational assets: Self-knowledge, diverse networks, openness to experience

How will companies manage longer lives and postponed retirements? When careers become 50 or 60 years long, they will want to move away from the current, linear career model that puts so much emphasis on the 30s and 40s. This should help parents, and especially women, who have been held back by the business world’s emphasis on the 30s as a make-or-break career decade.

Workers now in their 20s are eager for experience and are more mobile than they may be again for decades. The rise of assortative mating means that more and more people marry someone just as educated and ambitious as they are. This makes many people less internationally mobile than they were in the days of single-earner couples. International companies could start building cross-cultural skills much earlier (and/or much later).

Yesterday, companies were reluctant to employ both halves of a couple, fearing issues of nepotism. Tomorrow, they may shift to managing “family” careers by strategically choosing to hire both people. It may prove a lot easier to manage dual career couples when they both work for you. For many of the larger multinationals with big graduate training programs, a lot of people end up marrying a colleague anyway. Embracing this fact, and working with it, rather than ignoring or discouraging it, could optimize and encourage the skills of two people, rather than enmeshing them in today’s often painful tradeoffs and choices between whose career should ‘take the lead’ and who should “follow.”

The intensity of parenthood peaks between 30 and 35, on average; this period clashes directly with companies’ high potential identification and development policies. For decades, this has eliminated too many women from leadership pipelines. Longer life spans will render this short period of time even less significant than it currently is. Companies will want to manage careers with several talent identification periods, at different ages and stages, rather than just the one currently most common.

As people age more healthily and work longer, the 50s and 60s will emerge as creative new decades of renewal, mobility and wisdom. Aging societies may not be the sad and boring future everyone fears. They may be an innovative and promising reinvention of human potential. Smart companies are already working to make their talent management approaches more flexible, shifting away from the “ladder” and allowing individuals more say in crafting alternative paths along a “lattice.”

Finally, companies will want to integrate the consequences of much longer lives into all their products and services. There are huge new opportunities in analyzing and serving the needs of humans are discovering that life hold entirely new chapters. Moving away from quickly outdating stereotypes of aging, retirement, and recreation, to dynamic new images of re-creation and innovations in lifestyle choices is fertile territory. For example, the over-60s entrepreneur is the fastest-growing segment in the UK and people aged 55-64 started 23.4% of all new businesses in the U.S. in 2012, up from 14.3% in 1996.

Longer lives will also challenge companies that are already struggling to manage and adapt to the modern workforce – whether it’s adopting policies that work for two-career couples, protecting employees from burnout, or offering the training and development opportunities that 60-year careers will require. Companies have long wanted to ignore people’s personal lives, and compartmentalize between “work” and “life,” but smart companies may want to recognize the connections and support employees through a variety of transitions, both personal and professional. Not doing so may cost more in the long run.

The only thing that you can be sure of about the consequences of longer and healthier lives is that transitions will become routine. We will all need to become skilled transitionists, able to learn, grow and reinvent ourselves. Repeatedly.