Nearly 17 years ago, in the throes of new infant love, I jumped off the train my career was on and bought a ticket on the mommy track. While it's true that I jumped with my heart as much as my head, I also thought I knew what I was doing. I thought I controlled the ride. If you'd hinted to me then how long a ride it would be, I would've looked at you with polite scorn and asked you puh-lease to give me a little credit.

I expected my career to be a cozily familiar place by now. I expected that the salient points about raising teenagers were really being addressed in all those magazine articles. In short, I expected to know the steps of my life by this time. No one told me it was all improv.

If you've also hit this new age of surprise, maybe you'll recognize some of what follows. Maybe you'll want to start your own list of what keeps you a little off balance, the little stuff--and the big stuff--you never expected. Here, for the record, is mine.

The community closet

It never occurred to me that eventually all three females in our household would be wearing the same size clothing. Or that my bedroom would periodically be transformed into something akin to the Salvation Army, supplying good, serviceable used clothing to those in need--usually on school mornings when the hampers are overflowing and no one's remembered to do the wash. Fathers' closets are not exempt. Faced with the first really chilly day of the fall, my eldest daughter took off for school in her dad's favorite polartec jacket.

The community computer

It used to be my computer. My work space. Now my ace-up-my-sleeve evening work hours are homework hours, the computer is inaccessible until well past my bedtime, there are math books and report notes scattered around my desk in the morning, and not all of the apple cores and banana peels rotting quietly away next to the keyboard can possibly be mine. Just as I realize I have a firm one-computer-per-family ideal, I find it collapsing around me.

Literally, the change in perspective

Being the shortest one in the family means breathing hardest on walks and wanting to stop first. It also means, by some strange biochemical reaction in the female brain, automatically feeling fatter.

The joy of sophisticated banter

Teenagers are smart. They make jokes. Good ones. Their minds are mostly grown up and their hearts are young and the combination is very funny. Laughing at dinner is good for the digestion.

They can really do stuff. . .

I don't mean trigonometry or holding a job or saving the world--although they can do that too. I mean operating a washing machine, transporting the garbage from the kitchen can to the garage, cooking a meal. Remember all those child-rearing manuals that said, over and over, teach your children simple tasks. Let them help. Even if it's easier to do it yourself. They were right. Of course, how things get done, and when, and how willingly is another story.

. . .and that includes giving advice

First they started looking at me funny. Then they began to suspect that I actually do more than sign permission slips, direct transportation, stock the kitchen, and assist their dreams. They've become aware of mine. And they have opinions. Now it's open season on how I talk to friends, manage my work, arrange furniture, and spend money. And I listen to them. Annoying as they are, they just may be right. After all, after years of teaching them priorities, values, life skills, and compassion, I might as well see if the investment will pay off.

The real meaning of the mommy track

I fully expected that my leave-taking from my full-time job would be a simple hiatus, a few years, after which the work world and I would have an easily accomplished reunion.

It didn't work out quite that way. After years of part-time work, contract work, freelance work, and no work at all, some days I'm convinced the mommy track is the one you lie down on while you wait for the trains to run over you. Other days I cherish the freedom and the challenges of my patched-together working life. But I'm convinced now that, for better or worse, its ramifications are forever. I'm a different person than I would've been. So are my children.

The difficulty of starting over

Some new parents find a way to back off from their careers without leaving them. They're professionals with established practices who can simply cut down on work days. Or they remain with the same company, which knows their work and bleats with pleasure when they're ready to dive in again.

But for those of us who really left the places where we were known, whose employers were small and couldn't accommodate us, who find ourselves restless and wanting to launch out in new directions, it's harder now. It's great to be an enthusiastic beginner in your twenties; in your forties, it's a bit suspect. Further education becomes a slightly more dubious option when you're within a year or two of having to pay for college tuition for your children.

It can get discouraging. When it does, I recommend that you have lunch with your full-steam-ahead, mid-career friend who is also a mother. Her fatigue may not cure your depression, but it helps.

The rediscovery my own, young self

There it is in my daughter's poetry. Or her impatience to get away from home to make her own adventures. Her astonishment at the mess the world is in and her determination to do something about it. Her enthusiasm for learning, finding a path and following it. Making a life. On this wind of hope, even middle-aged dreams revive and float like feathers.

This can be a hard gift to receive, wrapped as it always is in the pain of looking back over the road by which you've come. And this in an exhausting season of life, when everyone's choices are called into question by the sheer effort of the long haul of parenting. Still, in the midst of it all, remembering who you used to be can help point your way ahead.

And finally, the most recent surprise. Just as I was becoming convinced that this ride would go on forever, the whistle began to blow. This train is approaching a station. Books on financing college and living in an empty nest are beginning to attract my attention.

I'm tempted to trade in all those useless assumptions I started working-motherhood with for a new set about what comes next. I'm resisting that temptation. I'm keeping my dancing shoes handy, and listening for a new beat. Because no matter what the next stage may be, it'll have a lot of made-up steps in it. A lot of surprises. Because this is life. It's all improv.

LAURIE BARON has traded the pleasures of working near the refrigerator for the privacy of a rented office, where all the banana peels are again her own.