As mothers, when our children are young, it’s our job to remember everything: Birthday parties, the dates and times of appointments with the pediatrician, when the summer camp applications are due, and – before we try to leave him at the kennel on our way to the airport - whether the dog is current on his vaccinations. Standing in the emergency room, alarmingly bloodstained, we must recall whether the child who just met a rusty nail is in fact the one who received a tetanus shot two years earlier. As mothers, our heads are stuffed with details, until we are certain that one more item on the list – something as simple as remembering to get pepperoni on one half of the pizza, but not the other – will cause a messy rupture.

Later, in middle age, just when you think you can safely stop reminding your kids to brush their teeth, it gets harder. Our maternal brains must continue to function as the central switchboard, through which all information is routed. If we’ve raised them right, adolescents will begin to do some of their own remembering. Unfortunately, they are inconsistent: The responsible young man who makes his own driving test appointment and reminds you of it ten times in three weeks must be pulled off the tennis court, sweaty and irritable, when it is time to sit down for dinner with Aunt Sarah. Mostly, we act as unpaid personal assistants, setting up and canceling appointments, tracking down books, ferrying supplementary meals over to the high school for hungry kids who are working on a project late into the evening. As mothers, we are quick to adopt a mea culpa stance. If we’ve neglected to remind a teenage child to rise at 6 am for a 7:30 date with the SATs, we know whose fault that is.

When that switchboard begins to fail - and for most of us, this happens somewhere between forty and fifty - those who have relied upon us are appalled. If you forget to make the traditional carrot pudding for Thanksgiving, or blank on the name of a teenager your child has known since pre-school, prepare to be awash in adolescent contempt. Dig deeper and you’ll discover that the kids are terrified that your internal hard drive is failing - that the archive will be lost. They have private memories, ones that you’ll never share, because thankfully, you weren’t there. But you’re still the Keeper of Who They Are. You, their mother, can tell them many embarrassing things about themselves that they’d prefer to keep buried in their unconscious. But you’re also the one who knew, way back in third grade, that one day they’d publish a novel, design a building, or find a way to make peace in this world. As mothers, we cling to those early memories, making regular forays through the photo albums we assembled when the children were small. Sometimes, to keep up the façade, we fib just a little – yes, of course we remember Jill, now 22 and impossibly beautiful, from the middle school soccer team. How could we possibly forget?

Dr. Michael Seabaugh, a clinical psychologist in Santa Barbara, California and author of Healthspan, a weekly column on healthy aging, is a new friend of mine. We met each other online, after he wrote a rather wonderful column about CARVED IN SAND. Since then, he’s been sending me his work. Here’s an essay of his I love so much that I asked him if I could put it in my blog. Fortunately, he agreed. I hope you enjoy it as much as I did.

As the old observation goes: Today’s sorrow, plus time passing, equals tomorrow’s comedy. Memory can be kind in that way. Today we cry, tomorrow we laugh.

We complain endlessly about our skeedaddling memories, yet there is more to consider than whether or not we can remember where we put our keys. Sometimes our unreliable memories can be most helpful and forgiving.

Think of it this way: We will often remember the giddy feeling of the champagne and not the hangover, ergo the tendency to pop the cork on that next bottle of bubbly. Women who’ve gone through childbirth tell me that if they could actually remember the pain they went through, they would never choose to go through it again.

According to the Nobel Prize-winning Princeton psychologist Daniel Kahneman, we tend to repeat experiences that seem more palatable in hindsight than they actually did at the time. In other words, our experiences and our tendencies to repeat them have less to do with pleasure and pain — as one might suspect — but more to do with our fallible memories of pleasure and pain.

I have noticed that we filter our memories differently. There are those who only remember the pain of life, ignoring the more blessed moments. And then there is the “half-full memory” crowd that only remember the good times, forgetting all those dark corners. I happen to fall in the latter category. People close to me will sometimes remark on my ability to forgive and move on. Truth is, I really can’t remember the pain and drain of those bad times. It is not some moral highness I possess; it is probably just good, old-fashioned denial.

In other words, the fidelity of our memories can be very much a function of our individual coping styles. Some will happily wear yesterday’s memories today like outdated fashions, while others will deliberately cut themselves off from memory, retaining no keepsakes from the past. Some will become overtaken by a memory in a way that they can’t escape; such is the case of PTSD (Post-Traumatic Stress Disorder). Of course, there is also the garden-variety neurotic who stews in the past, like some Woody Allen bobblehead.

There is the boon of not remembering all those terrible things we did once upon a time but wish we hadn’t. I remember my father saying that a man with a clear conscience probably has a poor memory. And then there is someone else’s father — Franklin Adams — who opined: “Nothing is more responsible for the good old days than a bad memory.”

And sometimes an abstracted memory can provide us with some of life’s greatest pleasures. Have you ever noticed there is no summer day in the present that compares to the remembered summer day from childhood where there was a swarm of fireflies on a balmy night that smelled of honeysuckle?

On the other hand, we must remember those who forget the past are more likely to repeat it in the future with potentially dire psychological and interpersonal consequences.

So what is better? The harsh comptroller of exact memory, or the more romanticized sieve of memory? It’s hard to say. One thing to consider is the well-researched finding that optimists do live longer. And it does seem that to be an optimist you need an errant memory. So maybe the fallibility of our memories — something that can cause chaos in the short run when we are trying to remember why we just walked into our living room — can be a boon to our longevity.

One of my mother’s favorite sayings is, “My imperfect memory has served me well; it has given me roses in winter.” This lovely and lively woman will be celebrating her 87th birthday in fine form next month.