No simple answers, but thanks for asking

I hope none of the major polling firms are planning to include me in their next roundup of public opinion. But that doesn't mean I'm apathetic. Just the opposite is true. I don't have time to help the big boys do their surveys because I'm usually too busy polling my own behavior and beliefs, and the answers I get are often inconclusive.

"You having a good day?" I think this question, or variations of it, is probably spoken millions of times across America by store clerks who are trying to make cheerful conversation with customers. I won't argue with anyone who finds it annoying or trite, but for me it's a useful avenue of inquiry that resonates long after I've passed through the checkout line.

As we grow up, individual assessment is part of the education system. Having a good or bad day in school can be monitored using a variety of well-established benchmarks such as passing tests, turning in homework, and teacher evaluations. But one subject that isn't given enough attention is how to set up our own assessment procedures for life in the adult world.

Have you devised a set of standards for measuring personal performance? Do you aim for a specific goal or achievement that will determine whether you've had a good or bad day? My own admittedly loose guidelines for navigating the currents of modern life are based on what Spencer Tracy once said are the keys to good acting: Show up on time, know your lines, and don't bump into the furniture.

But as we all know, the presentation of the everyday world is mostly unscripted, and there are numerous scenes that call for quick improvisation. It often happens to me while driving. Recently I took improvised evasive action to avoid a car that had crossed the center line and nearly hit me head on. Was that incident a good or bad part of my day? For that answer, I had to move Spencer Tracy into the wings and turn to my inner Rumsfeld.

No sarcasm intended here. Last December, Donald Rumsfeld chided the media for putting too much emphasis on American casualties in Iraq, and he wondered why similar attention wasn't focused on the thousands of US traffic deaths that occur annually. Critics of Mr. Rumsfeld's war policies hammered him for trying to make a connection between Iraq and highway safety, but as I studied the two subjects objectively an amazing synergy emerged.

Looking for good news in the midst of a bad situation can be a useful method for sorting out the significance of our daily activities and experiences. When that car coming at me swerved back into its proper lane, raced past, and then disappeared into the distance, my inner Rumsfeld said, "He missed. That's a positive development." In this case, I agreed.

But don't get the idea I'm trying to promote a rosy world view based on negative events that fail to occur. There are an infinite number of ways to debate how each person changes the world, and is changed by it, with good and bad results. So whenever a clerk asks me how my day is going, I usually just nod and say, "I'm still in it. And looking forward to the next one."

• Jeffrey Shaffer writes about media, American culture, and personal history.