One fine day as I idled at a red light in Allston, Massachusetts, two hopped up guys stepped into my cab, trained a gun on me, told me to turn off my dispatch radio and drive up Summit Avenue to the top of Corey Hill, where they were going to shoot me dead.

(Note to self: lock door at red lights.)

Something in me said it would be a good idea to keep the vehicle moving and not stop. So instead, I drove my passengers up to and over Corey Hill and right into Brookline, where I pulled into the curb outside the Brookline police station. They disembarked and slithered away without a word.

They did not tip me. They did not even pay their fare. I did not complain.

I was in my early twenties, learning something about the world by driving taxicab, which I did for about six months. At the time I thought I was doing it purely for the much-needed income, but four decades of hindsight tells me I also needed to do something that would stretch me and force me to grow up a little.

Driving taxicab outside Boston certainly did that.

I stretched and grew in that job — but I also hated it.

I hated it not so much for the danger, but because it felt like taking a long walk in a pair of shoes that didn’t fit. The job didn’t really use any of my strengths. Some people have a naturally outgoing, chatty nature and love spending time striking up conversation after conversation. I am not that person.

I had a friend at the time, exactly my age, who also drove cab for that same company. In a short time he graduated from cabbie to dispatcher, and was one of the best dispatchers Red Cab of Brookline ever had. He eventually had his own transportation company. He had a natural feel for that line of work. I did not.

Driving cab was good for me at the time, perhaps, but if I’d had to keep doing it for years? Misery.

Just because you can do something doesn’t mean you should do that thing.

My mom once observed: “If you’re in a shipwreck and you see the top of a grand piano floating by, by all means grab it and hold on. But just because that works doesn’t mean we should start making life preservers the size and shape and weight of grand piano tops.”

Driving cab worked—but it wasn’t what I loved doing. It was a life preserver fashioned out of a piano top.

Here’s how Martin Seligman, the father of positive psychology, describes the difference between a job, a career, and a calling:

a JOB is something you do for the paycheck;

a CAREER is work you’re deeply invested in, because in addition to paying you, it also advances your path by developing your abilities, your experience, and your ability to earn higher pay and more prestigious positions;

a CALLING is work you do for its own sake, work that is fulfilling in its own right. It is work you because you love it.

I learned about love of work from my father.

In our home dinner was a nightly family ritual, complete with candles, cloth napkins, and roundtable conversation about whatever had gone on that day. After dinner we cleaned up—and my father went back upstairs to his home office to work, and he worked at his desk until 10:30 or 11:00.

He not only brought his work home with him, he also brought it on vacation. I have vivid memories of weeks spent on Cape Cod, my father in his bathing suit poring over a manuscript in a corner of our little rented beach cottage, putting in corrections with red pencil for a few hours before setting it all aside and going for a swim.

It never occurred to me that any of this was the behavior of a workaholic, for the simple reason that it wasn’t. He simply loved his work, and he pursued it with a kind of relaxed intensity that never allowed it to hold the rest of his life hostage.

When my father reached retirement age he earned the title “professor emeritus” — which didn’t mean he stopped being a professor, it just meant he now had far more freedom of choice as to which seminars he would teach, which conferences he would attend, and which writing projects he would undertake.

I remember his exact words: “Thank God I’m retiring — now I can start getting something done!” And he went right on doing the things he loved to do.

For the last few days I’ve been completely immersed in a project to revise and enlarge an early book of mine and prepare it for self-publication on Amazon Kindle, Amazon CreateSpace, and Apple iBooks. I’ve never done this before and there’s a ton to learn, as I’m doing it all myself. I could pay someone else to do it. (It doesn’t cost much.) But I’d rather get my fingers into the dirt and soak up every detail about exactly how the process works.

In that wonderful film Patton, George C. Scott as General George “Old Blood ‘n’ Guts” Patton stands at the edge of a battlefield surveying the chaos and smoke and carnage, and murmurs, “I love it. God help me, but I do love it so.”

That’s how I feel about building a book.

What is it that you feel that way about?

My friend Dan Burrus says everyone has many skills and talents, but one true gift. You could spend your entire life using your skills and talents, says Dan, but the secret to happiness is finding your gift, and then wrapping your career around that.

How do you know what your gift is? I can’t say for sure, but I suspect love will be involved.