If you don't spend a lot of time around children, you run the risk of losing touch with how they think. And it's good to stay current, not just because they may have your power of attorney someday.

Consider this: Yesterday was Earth Day. You quite possibly ignored it, but there are a lot of green messages aimed at children these days, and Earth Day is kind of a big deal for small fry. Like the metric system was 30 years ago, when I was forced to learn how many hectares are in a deciliter.

But are the kids really going green? Are there really youngsters like that boy in the commercial who makes his dad brush his teeth from a cup and buy soft-serve light bulbs?

Sitting in LaGuardia Airport, I became aware of a conversation behind me between a very small girl and her mother, who were having a snack.

"I like cimanim," declared the little girl.

"Cinnamon," Mom corrected.

"Cima … cima … "

"Cinn. A. Mon," said Mom.

"Cinn-a-mon," echoed the child carefully.

"Now let's get things cleaned up and put away because we'll get on the plane soon. Is this garbage?"

"Some of this is to recycle," the tyke corrected.

Whoa. She was maybe 4 years old. At that age, my idea of recycling was sticking chewing gum to the side of a glass for later.

On the same trip, another child gave me a lesson in how much things change while staying the same. I never saw either the boy or his companion, because they were walking behind me in Manhattan.

(While you can overhear some uniquely colorful conversations in New York, it is usually best not to turn around and look directly at the people having them.)

"If you step on a crack," the boy began, in a serious, almost professorial tone, "you burn your foot."

That's not the way I heard it. But a lot has changed since I was a kid. Perhaps the crack-stepping penalties have shifted from family members to focus on the transgressor himself, thus de-incentivizing crack-stepping among naughty children with objections to parental discipline.

"If you step on two cracks, your whole foot blows up."

This was also news to me. I wondered if it was at all troubling to my young companion that I was stepping all over cracks and my feet had, so far, not burst into flames.

You'd hate to see that happen, wouldn't you? Melt a perfectly good pair of pantyhose.

"And if you step on one of those metal fence things in the sidewalk -- you know? Those metal things? -- you explode."

Well, it almost happened to Marilyn Monroe.

And here I was avoiding subway grates because they emit radioactive steam (or so David Letterman always said) and shred high heels.

Not that the real-life video game this kid was setting up doesn't have a certain appeal. I had to admire the violence of his imagination; he sounded like a perfectly nice kid who was in town to go to a museum with a rich aunt or a memorial service for an elderly great-uncle with his well-educated mother, who wears a dainty and expensive watch.

(It's amazing what you imagine based on the way people talk. That's why meeting people in radio is almost always disappointing.)

Still, I couldn't help wondering: Does this kid really believe this? I mean, it's absurd on the face of it and easily disproved, but when has that ever stopped people believing ridiculous things?

Somebody keeps the late-night chat lines in business, because they evidently believe that gorgeous local lingerie models have nothing better to do than talk to weird strangers on the phone.

But the boy behind me was firmly grounded in reality:

"And you get three lives," he finished.

Sure you do. You're recycling.