Awakened from a deep sleep, a friend recently recounted how he walked to the dresser, turned on the light and, catching a glimpse of himself in the mirror, wondered, "How did I get so old?"

Another friend who just turned 39 said he felt as if he were aging very rapidly. "I'm an old man," he wailed when I called to wish him a happy birthday.

Having long ago made the leap from the third decade to the next, I thought he was taking to the mat much too readily in his last round with his thirties until I realized what he was really worried about was his biological clock running down.

Because U.S. culture is still so much kinder to men as their hair thins and their waists thicken, their anxiety about aging prompted me to think a little about this process in my own life.

I decided to consult my college daughter, who was ending a holiday visit. "Ummmm, does my face look a little . . . drawn?" I asked. She drew close to me, leaned over and pretended to count the tiny lines around my eyes. "Vanity, vanity," she laughed, dismissing me with the wisdom of the ages, "all is vanity." Somehow I was beginning to know how Rip Van Winkle felt when he went to sleep young and woke up old.

But what did she know? For her, the process of getting to be 18 seemed eternal. Whereas she could hardly wait to grow old, I, on the other hand, turned the pages on my years and charted my growth by watching her and her sisters age.

Over those years, the meaning of age has shifted dramatically. Gloria Steinem spoke for us all when she said that turning 50 today is what turning 40 used to be. But middle age by any other number is still middle age.

According to the Census Bureau, America is graying so rapidly that, in a few years, the majority of the country will be old, raising the specter of age wars as the older generation drains off what some feel is an undue share of the nation's resources. And it is very disconcerting that baby boomers are turning 40 this year.

But it is at times like this that I remind myself that a person is only as old as she thinks and feels and that age is affected by a host of factors. For example, if you see a person every day, you hardly notice that the person is getting older. Indeed, you can even forget your own age -- until you see someone whom you haven't seen in 20 years walking toward you down the street. Pausing to exchange a few remembrances, you think to yourself, "My heavens, she looks so old!" Then, as you walk away, you realize that she is actually six months younger than you are.

Then of course there are all the things that we do to maintain our illusion of whatever age we are. Some people jog. Others play tennis, basketball or ride a bicycle.

But I think it is well to remember that while youth has its place, some things get better with age. While National Football League players, even Super Bowl champs, deteriorate with age, the abilities of writers and painters, like wine, often improve with maturity.

And increasingly, women are viewing the years from 40 onward as a time of new self-definition, of releasing old fears and other people's perceptions of whom they should be. One of my friends remarked that when she reached 44 she felt like she was "finally a grown-up." By contrast, a 35-year-old woman I know confided that she had so many choices that it was confusing. "You over-40s women who have married, had kids and worked, or maybe divorced and even started over again, have the best of all possible worlds."

And old men have always been favorites of poets, playwrights and preachers. Yeats loved his wild old men, writing in "Girl Songs" of "a young man old or an old man young." The biblical Methuselah lived to be 969. Although as Gershwin put it in "Porgy and Bess," what good is being too old anyway when "ain't no girl gone give in to a man who's 900 years . . . . "

But since we can do little about this inevitable process, I'll pledge to deal kindly with myself as the seconds of time tick on, because the truth is, I feel better with each passing day. And just in case of any momentary lapses when I might fleetingly feel threatened by the absurd cult of youth in this society, I promise to moan very quietly a spiritual I used to hear my mother sing: "Never grow old . . . . Ne-ver grow old . . . . "