About 11 years ago, on the first day of my eldest son's kindergarten year, I lingered by the classroom door.
I was waiting for the bell to ring and for his first teacher to whisk him away to his new life, one over which I would have little control.
There were a few awkward moments while my son and I stood there on the blacktop, wondering who would leave first. Then he asked me if I really wanted to wait. I looked around and saw plainly that I was not the only parent there.
"I'll stay," I answered.
"Okay," he said, and then he ran off.
It was the beginning of letting go, and every parent there that day knew it. We had tried to shield them from the free-ranging harms of the world. We'd taught them not to talk to the man pulling over to ask for directions, to ask for help from a woman with children if they were ever lost at the mall, to never open the door to a stranger.
But we knew, on that first day of kindergarten, that we could not really protect them forever. We would have to send them into the world, first to school but ultimately to other places, too.
So we put our kids on the school bus, let them go to a movie, give them the OK to attend a sporting event. We tell them to be cautious because we hope common sense will provide a level of safety, but we also believe, finally, in the basic decency of the people they will most likely encounter.
Until it happens, we can't imagine a lunatic mowing down elementary-aged kids like they were nothing more than paper targets at a range, or a deranged student at a movie theater systematically shooting those he calmly sat next to only moments before.
And before last Monday, most of us were unprepared for someone who might attend a marathon with a bomb in a backpack.
On the day of the Boston Marathon attacks, President Obama promised justice. But every parent knows there cannot be justice in such cases. Justice carries with it the notion of payback, of righting a wrong, but nothing can ever mend the damage of a dead 8-year-old boy and his surviving little sister, a girl who will now go through life with a prosthetic leg.
Even if the killers are caught, they could not in an eternity serve enough penitence to heal the wounds.
After the Lockerbie bombing, I adopted the habit of checking out passengers when I boarded a plane.
What I was looking for were children. Surely, I thought, not even a terrorist would attack a plane with children on it, and so their presence on an airplane was a promise of security.
But then Timothy McVeigh bombed a federal building in Oklahoma, killing 19 preschoolers, and I realized the stupidity of believing that anyone capable of random violence might also possess a conscience where children are concerned.
Since then there has been Columbine, Virginia Tech, 9-11, Tucson and so many other instances of meaningless violence that I cannot keep track of them. But they all have one thing in common.
They have all been committed by men who were, in essence, terrorists. They wanted nothing more than to make others suffer.
Humans have always been violent, of course. Our capacity to inflict pain on our own kind is unmatched in any other species.
Over the course of history, though, the carnage has usually been a means to an end, not the end goal itself.
But there is nothing we can give terrorists, whether they are the homegrown kind, the crazy kind or the fanatically religious kind, that will make them stop committing acts of terror.
It is death itself that they want, and each time they create it, they have achieved their aim.
I am still, as a parent of minor children, learning to let go. Each day I send them out into the world, to school and to sporting events, trusting that they will return to me whole once again. But I no longer believe in the basic decency of the people they might encounter.
Brigitte Bowers is a lecturer in the Merritt Writing Program at UC Merced.