It’s curious what happened to curiosity. I started wondering after I returned from a posting in Africa some years back. Bubbling with stories of beauty and tragedy, I’d wait for my turn in conversations.

“Africa?” someone would interrupt. “I just saw a show on the Discovery Channel” The discussions would thereupon revert to the familiar: TV, celebrities, sports, the latest fad diet or what to wear for casual Fridays in the office.

Later, I gained some perspective. On assignment in the Alaskan wild among homesteading families, I received a different reaction. When I mentioned Africa, people quieted and circled around.

I hadn’t suddenly regained the capacity to tell a tale. I had simply wandered out of the orbit of the Information Age. That gave me a line of sight on what all that information was costing us. Namely, our curiosity.

There’s no surprise to saying we are oversaturated with information in urban America. We’ve been struggling to tame it since about 1970, when Alvin Toffler published “Future Shock.”

The statistics are numbing: According to various experts, urban Americans are bombarded with 10,000 to 30,000 commercial messages daily, plus an additional 200 or so personalized messages in the form of telephone calls, e-mails, faxes and memos.

And then there’s the daily news in whatever dosage you can tolerate. I cannot find the clipping, but I did read that we spend 150 hours a year searching for lost information.

What I’m aiming at is not the problem, however. It’s the problem with the solution. Ever ingenious, we respond to the assault on our senses by deploying fine-mesh information filters. Information we want, or need, passes through, and the remainder we disregard like mosquitoes buzzing outside the netting.

Just ask anyone you know in advertising. They’re pulling their hair out trying to find creative new ways to pierce our defenses. When they discover one, we add a patch to our filters.

What I found among homesteaders along the Arctic Circle were people who had not yet enclosed themselves behind protective information screens. When you’re 75 miles from a road, a billboard is still a novelty. Nature was intact, including human nature’s gift of the receptive, searching mind.

In the city, even among friends who pride themselves on their worldliness, the only world that reaches them is what they have programmed their filters to recognize. Africa got shut out with the mosquitoes.

Although we don’t dwell on the subject consciously, I think we recognize the flaw with this survival strategy, if not yet the remedy: deciding in advance what will be interesting and important significantly narrows our thinking. For one thing, we reduce our chances of serendipitous discovery, of encountering something unexpected and wonderful, the sweet fruits of curiosity. For another, we wind up confining our civic discussion to just a handful of pressing social matters. Often, as a further check against overload, we sift these down to the simplified pap of sloganeering.

Now, with the elections upon us, we kick ourselves for the self-defeating consequences. Another campaign has passed without real debate and only formulaic discussion of… well, take your pick from a dusty ledger-book of topics that should ignite our passions, stir our imaginations and surely appeal to the curiosity of a people who have empowered themselves to set the course of their own governance.

No need to wander all the way to Africa, either. We can look in the mirror at something as urgent as the health system: At least 41 million Americans lack medical insurance.

Emergency rooms, already the shame of many communities, are threatened with closure. Nurses are in short supply. Doctors are again cutting off Medicare patients as unprofitable. Our blood supply depends on the willingness of the destitute. The deregulatory fundamentalists have left our food supply dangerously vulnerable to contamination. The national public health system is still unprepared for the terrorist attacks that we are told are certain to come. If gasoline were rising in price as fast as health insurance premiums, we’d be paying $5.30 a gallon in just a few years.

Oh, but speaking of health care, did you watch “ER” on Thursday, when that patient had a flesh-eating infection?