The simplest policy for coping with other people's obstreperous children in public places is avoidance. You detour, you ask for another table, you change seats or you just leave.

It's a far cry from my own distant childhood, when it was understood that any adult over the age of, oh, about 25, had automatic license to issue brief, peremptory instructions to any child younger than approximately 15, such as "shut the screen door" or "quit making that noise."

You can't do that anymore. Even the most negligent mommy or daddy can, and often will, take offense at the intervention of a stranger.

So I promise I won't try to discipline your kid. But here's your end of the deal: Kindly don't expect me to help you parent.

This awkward situation posed itself the other day, when I stopped in at a cheery neighborhood market. The meat counter guy had promised me a supply of turkey wings (for use in making my Thanksgiving gravy, which, I must modestly state, is excellent).

The store was crowded with after-work shoppers, and one hyperactive child was making herself awfully noticeable.

She was about 5, wearing a sweet little pink T-shirt with a rainbow-hued peace sign on the front. She behaved as if she had ingested about a dozen cups of double espresso.

Oblivious to her mother's fond entreaties – "Francesca, watch where you're going," "Don't lick that, Francesca, it's dirty," – she ran up and down, rocketing around the displays and pawing the groceries, using her Outside Voice to holler back at her mommy.

(For the record, her name was not Francesca. I don't want to risk embarrassing a child.)

Like the other adults, I just dodged out of the way. I tried to hurry along the turkey wing guy. But while I was looking the wrong way, the child smacked into me, hard, at hip height, knocking me back against somebody's cart.

I have written about similar experiences in the past, wherein parents behave as if they're oblivious. Having trained themselves through sheer endurance to tune it out, they expect you to do the same.

To her credit, Francesca's mommy was not oblivious. Francesca's mommy viewed this as a teachable moment.

"Francesca! You ran right into that lady!" she scolded. Heads swiveled. I felt conspicuous.

"You have to watch out for people! You have to look where you're going!" she continued. "That lady didn't see you coming! You could have gone around her!"

It was beginning to seem a little as though I bore part of the blame. The woman spoke as if I were an unexpected obstacle, or a feeble centenarian who had blundered into moving traffic but is entitled to special consideration due to advanced age or infirmity.

"Tell that lady you're sorry, Francesca! You have to learn to be polite – say, 'Excuse me'!"

She continued talking to the child in this vein, referring to me in the objective case, as if I were an umbrella stand that had been knocked over. She didn't speak to me at all; it was apparently my job to stand there as a mute prompt to help Francesca learn the rules of polite deportment.

"What do you say, Francesca? We're not going to Zoe's house until you tell that lady you're sorry! We're just going to stand right here!"

I imagined somebody at Zoe's house, glancing impatiently at the clock and remarking, "They're late – Francesca must have plowed into somebody at the grocery store again."

Gratefully seizing my bundle of turkey wings, I murmured, "Really, it's all right."

It was an awkward moment. Everyone in the store seemed to be waiting for Francesca to speak her line, which she was not inclined to do.

She shuffled her little feet and sucked on her little fist and goggled at me, at that lady.

We stood there in a little tableau: the clucking mother, the staring child and me, playing the role that fate always seems to stick me with – hapless bystander, hot with the embarrassment of unsolicited attention.

Nervously, I smiled, shrugged – hey, I've got to be going now! – and walked quickly away, leaving the mother in mid-prompt. She broke off abruptly, stunned, I guess, by the rude abandonment of my extemporaneous role in her child's social development.

"Oh, well," I heard her say disapprovingly – learning opportunity lost. Francesca, off the hook, giggled merrily. Neither the child nor her mother had addressed a word directly to me.

It was a little incident, but a telling one. I'm all for parents teaching their kids civility.

But it's not my job to help them do it.