By the end of this story, you may like me less.

But this is a story that might be good to tell, and it truly was one of the most formative moments of my life. You know that question—if you could go back in time and do just one thing over, what would it be? Here’s my answer.

Once upon a time, when I was a sophomore at a Catholic girls’ school, an unusual student walked into the cafeteria. She was not in uniform, so she immediately stood out among the hundred or so of the rest of us, all clad in our gray-and-navy skirts and sweaters. So being out of uniform…that was the first thing that set her apart.

The second thing was that she was pregnant.

Mind you, this was a long time ago, and things like daydreaming or wearing the wrong socks could warrant you a detention. My principal was appropriately strict and (in our youthful minds) somewhat terrifying. Bad behavior was not tolerated. Girls were expelled for drinking or smoking. Nuns would prowl the parking lot after school, looking for rolled up skirts and trashy behavior. If you wore too much makeup, you’d be asked to wash your face.

A pregnant student…at our school? Unbelievable.

She was very pretty. She had red hair. That’s about all I took in, because I didn’t want to look directly at her.

That first day, she came into the cafeteria, which quieted considerably at the sight of her, and sat at the end of my table. Alone, surrounded by empty chairs.

I was not a popular girl, but I had a group of friends, and we ate together every day. Mind you, this was the first time in my life that I felt like I belonged. My early adolescence was miserable—I was a tremendous geek who didn’t have the right clothes, did have a terrible haircut, Coke-bottle glasses and acne. I was teased. Bullied a little bit here and there. It was only now, at this school, that I’d finally started to come into my own. My own place was not cemented, in other words.

I don’t believe she was a student in our school before that year. Girls who were in her classes were pumped for information. How could Sister Mary, who was so strict, let a pregnant girl come here? It didn’t make sense. Not only that, there were rumors that Sister Mary had hugged her.

The girl ate without looking at anyone. I kept an eye on her, promising myself that if she looked at me, I’d invite her to sit with us. She didn’t.

The next day, the pregnant girl returned to the caf. Again, she sat down, alone, at the end of our table. Again I made that promise. Just look at me, and I’ll ask you to join us.

How ashamed I am—still—that I lacked the courage to get up and befriend her. That twenty-two minute lunch period lasted a lifetime. A hundred times, I told myself to do just get up and talk to her. I didn’t. No one did.

In that school where there were crucifixes in every room and the golden rule was something we could babble from the age of three, I sat there, not doing unto others as I’d have others do unto me, waiting for lunch to end. If it was long for me, imagine how it was for her.

On the third day, I vowed I’d do it. I’d set my tray down across from her and just say hi. But when I got to the caf, I saw that someone else was already there. Someone who, until then, had never seemed terribly special to me, yet had the grace to sit down with this girl, smile and offer her friendship.

And so, relieved that someone else had done the job (which was, at that point in my life, the greatest act of kindness I had yet seen), I went to my customary spot.

A few months later, the pregnant girl left our school to give birth and give her baby up for adoption. I don’t think she came back.

I’m not sure I’ll ever forgive my 15-year-old self for doing nothing. I haven’t yet. I knew it was wrong to leave her there alone. I thought about doing the right thing. I planned to. I didn’t.

I believe that experience slapped me good and hard upside the head. That it taught me the shame of failing a fellow human and deliberately turning away from someone in need. For all these years, I’ve remembered how I didn’t offer that simplest and most profound human gift: kindness.

It’s not that I think I’m a terrible person. I mentor, give scholarships, spend time and money on good causes. I tell people how much they mean to me. I carry groceries to cars, I’ve changed someone’s tire, I recently helped an elderly man off the plane when an evil flight attendant ignored him. I have an affectionate word for every child who crosses my path. When babies cry, I try to help. When I saw the weeping wife of a soldier who’d just left for Afghanistan, I hugged her and gave her my handy tissue pack. I hope I’m a nice person. I do try.

But I can’t forget those two days when I was stuck in my damn chair, unable to move a few seats down and make friends with a lonely girl who desperately needed one.

How I still admire Suzanne for sitting down with that girl! How I respect Sister Mary, who welcomed that girl to our school. And how I wish that I could go back in time, plunk my tray down in front of her and say, “Hi. I’m Kristan.”