Margaret Clark, 54, can't see her way to the bonus decades. She and her husband have two teenage children. Ahead of them loom college tuitions. She is working full time and loves her editing job.

Yet Clark is pulled by a psychic undertow. Her daughter, 13, just celebrated her bat mitzvah. Her mother died three months earlier. "The juxtaposition of these two events put me at a crossroads," Clark says. "My daughter is grown up. I'm not a daughter anymore." Who is she?

"What am I supposed to be doing now? I never had to ask myself that before," she says. "You go to school. You go to college. You have a career. You hope for a relationship. You get married and have children."

And then what?

This is the big churn that hits people in their fifties and sixties -- a time of reckoning and renewal. You don't have to have a crisis to feel unsettled. The drumbeat of anxiety is a psychological messenger that the rules of human development have changed. Instead of coasting after age 50 or 60, you have to gin up for an unprecedented next chapter.

"There are some huge choices," says Clark, who lives in Arlington. "If I want to live consciously, I have to make choices. I could muddle along and get to 65 and say, 'Whoops!' But I'm not like that."

Clark and her husband, Ralph Silverman, 53, have had different lives from those now in their seventies. They married later and had children later. They both have careers -- in fact, they met on the job. Their work patterns differ from the old style of employment where a person, usually the man, stayed in one job for decades, hopefully building up a pension, while the other, usually the woman, spent many years as a homemaker.

Clark and her husband both worked full time while their children were very young. Then she stayed home for seven years. An editor with a law degree, she continued to write on labor and employment issues as a freelancer. When her husband was nearly 50, his office was shut down. After more than 20 years at the company, he received a severance package. And so they switched work roles. He is now staying home and taking on freelance projects while she works full time.

But that is likely to change. How are they going to pay for college for the kids? Build up savings for retirement? As Clark says: "We're going to need to make more money."

Clark and her husband are still in the zoom zone of earning a living and seeing their children into maturity, but they are undergoing changes that bring them closer to the mind-set of the "My Time" phase of adulthood.

Part of the shift is due to the losses that people suffer by the time people get to 50. Some are small and manageable -- creaky knees, eyes that require glasses to read the menu. Some are major, such as the death of a family member. In the past year, Clark lost not only her mother but her older sister as well. When she thinks of her mother, who died at 93, she realizes, "I could live 40 more years. I better figure out what to do." When she remembers her sister, who died at 67, she realizes, "I can't dither around and think I'm going to do it all some other time."

And so she swings between a sense of potential and a sense of urgency, the internal hallmarks of bonus years. "There are so many unanswered questions and possibilities," she explains. "There's no road map."

Sometimes when she listens to people her age whose children are grown, she gets a twinge. "They are giving up the world of work, playing with their grandchildren," she says. "I'm going, 'Omigosh . . . when is it going to be my turn?"

As she says: "The difference between me and them is the kid factor."
For many people, the kid factor postpones the transition to My Time. But it shouldn't postpone thinking about what-next. As Clark says: "It would be extremely easy to blur through the next five or 10 years," focusing on children and job and not letting the unanswered questions come into her brain. But that would be using the kid factor as a form of denial.

"I don't want to wait," she says. "I'm here in this stage of life -- regardless of my children." That puts her in two places at once: continuing in the zoom zone and pondering an uncertain future. "No complaints. It's just challenging," she says.
The first step in preparing for My Time is to recognize the new reality of this bonus period. Clark's transition to a next chapter may take many years. That's normal. After all, adolescents can take a decade or more to make the transition from childhood to starter adulthood.

In this second adolescence period, you need time to shift internally from middle adulthood to the "extra" decades. You churn. You dream. You loosen up.
This week, Clark is taking her daughter to Florida for girl time. Her son is staying home with her husband to do guy stuff, she says. This is a special trip. She's still a mother. And she'll always be her mother's daughter. It's just going to be different. She wants to solidify the mother-daughter relationship "as we march on to the future," she says. It's also a "gift to myself: Do something really cool, really impractical, really frivolous."

All in all, a good start on the long journey toward regeneration.