Our oldest child is nearly three years old.

She is almost the same age as Christine Hanson when she died. Christine was traveling with her parents from Boston to Los Angeles a year ago, when terrorists hijacked her plane and flew it into the World Trade Center.

Of all the imponderables that took place a year ago this morning, this one still has me shaking my head in disbelief. To the terrorists, the people inside their intended targets -- the buildings -- were faceless. But they had ample opportunity to see, even to interact with their fellow airline passengers. Unfortunately, according to the calculus of these fanatics, the passengers were infidels, used to help many more infidels come to their ends.

But what kind of monster can stare a two-year-old in the face and still commit her to a fiery death? What cause, what abortion of logic, killed Christine Hanson for the crime of being born American?

That's the question I cannot shake, the vision I cannot solve. Now, a year later, when I have a child the same age as Christine -- one whose version of the alphabet still goes "ABCDEFGHIJK emmanumma P" -- I have to wonder what she could possibly do, what Christine could have done, to invite such horrors upon herself.

The answer, of course, is nothing. Two-year-olds are innocent. But make no mistake -- Christine Hanson wasn't a 'victim' of the terrorist attacks. She was a target. We all were targets that day -- most of us just didn't happen to be in harm's way.

Every time that I think about what happened on that beautiful September morning, I have this deep-felt need to give my child a hug and get her to sing the alphabet song again. I'm fortunate in that way, for though I've felt a great deal of anguish over the attacks, I did not lose anyone close to me. Most of us didn't. Christine Hanson's parents were with her on the plane, but she has other family. Were they to read this, certainly they would say, "Yes, but she wasn't your child." And they're right. The vast majority of Americans are mourning for a group of people they never met. They are not ours, and yet we wish to honor them. And we grieve for them all the same.

Sometimes I love my job; other times, not so much. I write about the comings and goings of American companies. It's enjoyable, for sure, if you enjoy the components of the chase of superior investments. And yet sometimes it just feels... empty. I think I know why. It's because investing, the process of buying and selling, of studying, of generating gains, is largely devoid of meaning.

I read a few years ago about a guy who was giving up a professional baseball career to devote his time to day trading, and I couldn't help but feel sick to my stomach. I wouldn't consider it a life well-spent to simply trade pieces of paper hither and yon. I felt this in the days after the attacks, when I was supposed to remark about how they might affect the U.S. stock markets. In my head, I was screaming, "The markets!? Who cares?"

This was, of course, the wrong answer. The markets matter, and since more than 50% of all American households own stocks, they matter a lot.

But pursuit of gains in the stock market shouldn't come at the expense of, well, life. My two-year-old daughter is the love of my life. How many times have I been so busy with something "important" that I couldn't pay attention to her?

So this week, for this column, we're not talking stocks. I'd like to propose that with whatever time you normally spend researching stocks, thinking about the market, or doing whatever you do, you instead join the ones you love. Everyone around you has my daughter's "emmanumma," something unique and beautiful about them. Go. Find it. The market will still be here when you come back. Most likely, you won't miss it a bit.

Fool on.

Bill Mann, TMFOtter on the Fool Discussion Boards

Bill Mann is the senior editor for investing at The Motley Fool. The Fool is investors writing for investors.