My Aunt Rita told me the doctors suspect she may have cancer. Her daughter, of course, will accompany her for the biopsy and other procedures.

How frightened I was to think of anything happening to my very last aunt, the one who used to paint flowers in iodine on my skinned knees.

After these thoughts came the inevitable one that always springs up when I hear about catastrophes: Oh, what would happen if I were in my 80s and needed someone to take care of me?

Which is rather selfish shorthand for the Big Regret: Why didn’t I have children?

This regret rears its head especially at Christmas, a season that celebrates the birth of a baby that changed the world.

How telling that God chose to show up as a baby, rather than, say, a full-grown man, thus making babies even more precious in the eyes of the world.

In my 30s, I was an atheist and didn’t dwell much on that baby in the manger. Instead, I spent many an hour in a psychologist’s office, discussing the pros and cons of having a child.

Counselors tried to remain objective as we probed my ambiguity. One day, I would be absolutely sure that motherhood was for me, and then would flip-flop the next session.

Like many women of my generation, I thought that everything was in my hands, and that included having children or not.

When I returned to Catholicism, every Sunday I recited the words of the Creed: “We believe in the Holy Spirit, the Lord and Giver of life.”

However, that part about “Giver of life” didn’t really hit home. Instead, I continued in my self-deception about being in the driver’s seat when it came to babies.

Every Christmas, I thrilled to hear the Gospel story of Christ’s birth, and marveled at Mary saying, “Let it be done to me according to thy word.”

But it never occurred to me to say the same thing to God.

Instead, as the years passed, I went on waffling, using contraception and ignoring the church’s teachings. Every now and again I assured myself that we would have children “some day.”

What so many women like me fail to realize is that a woman’s body responds to an ancient timetable. Yes, maybe one woman in thousands can give birth at 45, but the truth is that a woman’s fertility begins to decline in her mid-20s.

The National Catholic Register recently ran a story about young Catholic women who had stopped using contraception and had begun following the church’s plan of natural family planning instead.

These women testified to the joy of surrendering control to God and learning to accept children as gifts, not problems.

Envy is a sin, I know, but that was my reaction to the story. As a result of my earlier inability to say “yes” to the Lord, I will never have someone who calls me “Mom,” nor will I savor the joy of a visit from grandchildren.

During the years when other women my age were building nests and having babies, I was hard at work in graduate school. Still, it is human to look back and wonder what our lives might have been like, had we taken a different road.

There were people we might have married, but did not, and jobs we might have taken, but turned down.

I am still learning that it is important to forgive our younger selves for foolish sins and get on with life now.

And as a writer, I am blessed with a second chance. I can tell women that it is crucial to realize that you don’t have forever, and some things cannot be put off indefinitely, especially marriage and family.

The big lie for many women is the belief that we can have everything. Huge salaries, fancy houses, late-model cars—and children too.

We are also deceived into concluding that having too big a family is a bad thing, which is as crazy as saying, “Watch out! You don’t want to have too much love!”

This particular falsehood has led to a dismal situation for most of Europe, where the population is dying out because people have limited their family size so severely that they are not replacing themselves.

Once we realize that God truly is the “Lord and Giver of life,” we can put children in their proper perspective. Raising them may cost money and entail sacrifices and may mean giving up many dreams.

But each year, the miracle of the Christmas story brings home the undeniable truth. The salvation of mankind hinged on one woman long ago saying “yes” to God.

And the sight of that babe in the manger, with Mary and Joseph just a heartbeat away, tells the whole story about children that still rings true today.

You can stack up all the diplomas in the world, all the dollar bills, and all the fancy titles. Add priceless jewelry, vacation homes and the most luxurious cars imaginable.

And still you would not have the utter wonder, joy—and eternal worth—of just one child.