Sometimes we need to get slapped around a little bit, even at an advanced age, to learn a valuable lesson. I got my comeuppance last Saturday on SEPTA's R5 line somewhere around Overbrook.

A bit of background before I detail my humiliation/enlightenment. I spent a career in journalism — six newspapers, 33 years — the last 19 of which were at the Inquirer. All along the way the article of faith was to always get it right.

A noble end, to be sure, but after a while, you can slip into the self-delusion that your calling in life has endowed you with eternal powers of truth, even during a train ride more than 11 years after your retirement.

I initiated my SEPTA journey with a check of its website beforehand. There I came across a page titled "Seniors Ride Transit Free on SEPTA." It then said, "Senior citizens may use one of the valid forms of ID shown below OR they may use a valid PA Driver's License or PA photo ID Card to ride on SEPTA."

Great! Riding for free, all aboard. So when the conductor asked for my ticket, I said the website said I can ride for free, and I called up the page on my iPhone. He said he didn't care what the web page said, adding that he'd been doing this job for 29 years, and I had to pay the senior one-way fare of $1.

I did, but I held fast to the notion that I was right.

When he made another pass for the tickets of new passengers, he elaborated that the free senior passes did not apply to trains. I reflexively went to my iPhone, and there it was in the third paragraph: "Senior Citizens, age 65 and older, can ride FREE, at all times, on SEPTA Bus, Trolley, Subway, and Norristown High Speed services (see below for Regional Rail)."

As I read on, my tail embedded itself between my legs: "Regional Rail rides within the State of Pennsylvania: $1.00 for all seniors with a valid form of ID."

Once I could take a step back from my embarrassing behavior, I realized that I had just provided a textbook example of what psychologists call confirmation bias. Here's the definition on Wikipedia: "…the tendency to search for, interpret, favor, and recall information in a way that confirms one's preexisting beliefs or hypotheses."

In retrospect, I researched my imagined free ride by going no further than the headline "Seniors Ride Transit Free on SEPTA." I won't blame my error on the SEPTA headline writer. As a former copy editor, I know you can't cram every detail into five or six words. No, it's all on me for shutting down the critical thinking once I found something that I thought proved my point.

If this mea culpa gives me a platform for a message, it is that confirmation bias is not confined to liberals or conservatives in political arguments, even though it is most often cited in such cases these days. It is a preexisting condition in all of us, that pernicious characteristic of human nature that rears its head when our pride of being right and saying "I told you so" becomes more important than the truth.

On disembarking at Jefferson Station, I sought out the conductor, whose name was Sam, and apologized. He said no problem. I told him that if anyone else flashed this web page as supporting evidence for a free ride, he might want to say, "Read the first three paragraphs." I wished him well, and we shook hands.

For a $1 ride, it was a valuable lesson indeed.

Bob Martin is a former Inquirer editor and writer.