Editor's note: CNN contributor Bob Greene is a best-selling author whose current book is "When We Get to Surf City: A Journey Through America in Pursuit of Rock and Roll, Friendship, and Dreams."
Bob Greene says the drugstores of America give people the illusion there's a remedy for every ill that ails them.
(CNN) -- Take a stroll through the aisles of one of the big national chain-pharmacy stores: Walgreens, or CVS, or Rite Aid.
You probably have done exactly that recently -- paying a visit to one of the big drugstores is something Americans do almost by rote any time we're feeling a little under the weather
This time, though, pay special attention to the array of medications that are on the shelves. Taking a close look at them will provide a lesson of sorts about why the swine flu emergency has caught most of us up short.
The multiplicity of medicines available for purchase at American drugstores is displayed with all the color, variety and showmanship of a carnival midway. There's such a dizzying assortment, offered to us in so many expertly marketed permutations -- if the medicines in the aisles weren't intended for purchasers who are, by definition, feeling lousy, the drugstore displays would feel almost cheerful.
The unspoken message in those aisles is:
Something wrong with your health? No problem. We've got you covered.
So if, say, you're coughing a lot, the question is not whether there's something to remedy it; the only decision you have to make is whether you want your medication as a menthol-scented rub, or as a honey-lemon liquid for daytime use, or as a 12-hour orange-flavored syrup, or as an ice-berry pomegranate freezable Popsicle-like concoction. (These examples are all real, by the way.)
Stomach in distress? Choose between peppermint thin-strips, or cocoa-and-cream tablets, or mint-flavored juice, or wild cherry drink. Hurting from allergies? Take your pick among coated mini-tabs, or individually wrapped liqui-gels, or pre-measured sinus rinses, or nasal strips in clear or tan hues (sized for small, medium or large noses).
We have become so used to our stocked-to-the-bursting-point mega-drugstores that we have come to regard the concept of purchase-on-impulse health cures as something close to a right. And that's just the over-the-counter items; the potent, prescription-only items presided over by the pharmacists offer the promise of even more muscular medical magic.
(A mitigating factor, of course, is whether the person feeling sick has comprehensive and affordable health insurance -- the chances of which are beginning to seem about as likely as the odds of holding the winning ticket in the 30-state Powerball lottery.)
There are terrible exceptions to our national assumptions about the ready availability of effective solutions to illness; those of us who have lost family members and beloved friends to forms of cancer that fend off all attempts at being vanquished understand that all too well. Yet in most cases we do tend to take it on faith that if a seemingly standard-issue illness comes, there's probably an answer to it waiting.
So when the first news of the swine flu outbreak, and of its potential implications, arrived, it didn't quite fully register. A possible pandemic? In a world as scientifically and technologically advanced as ours? Aren't we supposed to be able to keep such catastrophes at bay?
There is an analogy to this: It is a little like when a mighty river, after flowing peacefully for decades, angrily overruns its banks and destroys the towns that are near it. We may have gazed distractedly at that river for years, and not have given it a second thought. We fool ourselves into thinking we have control over the water -- until we don't. Then comes the reminder: There are forces bigger than our power to harness them, and we are ultimately very small in the face of nature's whims.
That is how it feels when, at moments like these, epidemiologists give voice to the idea of a pandemic. Isn't our civilization far enough along that such things are inconceivable? Haven't we, over time, come up with the necessary defenses to obliterate such possibilities?
We hope the answer is yes; this week, doctors have been saying that some existing drugs appear to be effective against the swine flu. The influenza pandemic of 1918 killed an estimated 50 million people worldwide. And that was in a world in which citizens visiting distant countries was a relative rarity. In 1918, no American could hop onto a plane and go to Europe for a week; in 1918, no one who lived in Asia or the Caribbean could board a jet to the United States for a whirlwind vacation.
For a long time now, we have talked with some pride about how small we have succeeded in making our world: how borders have become all but meaningless, how the globe has shrunk, how we all, in essence, now breathe the same air.
Which is why the unknown potential of what is happening now feels so ominous. When the first cases of swine flu were reported this month, there were people who, even though there was no evidence pointing to such a thing, asked: Could this outbreak be related to some form of organized terror?
But that question ignores a larger truth, one that has kept untold millions of families, across the world and across the centuries, awake deep into the night:
Throughout human history, illness with no easy cure has been, in and of itself, the very definition of terror.
The opinions expressed in this commentary are solely those of Bob Greene.