I ruined my favorite shirt by failing to secure the cap on a pen I stuck in the pocket, and the ink stain was indelible. It wouldn’t come out. I couldn’t soap it, bleach it, scrub it, cut it or cover it.

Memories are like that. And the funny thing is, often it’s not the significant, dramatic, big events that wedge their way into the dendrites and axon terminals of your neurons, but little things that might have come and gone without comment or impact at the time.

My friend Tim Fields talks about that in his memoir “Indelible Ink: Adventures of a Baby Boomer.” You would like it. If you’re a baby boomer, you’ll like it a lot. He shares 16 events written in indelible ink in his memory, each of which shaped his life.

What makes a memory stick?

“Sometimes a simple comment from a parent to a child or from a teacher to a pupil can have a profound effect on someone’s life,” he writes in the foreword. “Even a smile, a frown, a wink or a raised eyebrow can dispense indelible ink. A congratulatory pat on the back or a punitive slap on the cheek can remain in a person’s psyche for life.”

I want to reemphasize the power of the right word. Little comments, angry words, insults, incautious words spoken at the wrong moment or secrets spilled worm into our memories in ways and with permanence we cannot explain or anticipate. Heartfelt, sincere positive words can just as actively attach themselves to our memories and have a much more beneficial effect.

I can point to a dozen memories, good and bad, that stick in my psyche half a century after they occurred, which at the moment seemed of no consequence. Some were throwaway comments by adults, directed toward me, or toward another adult that I overheard.

As a high school basketball player, I wasn’t tall, but I was slow. Because I could shoot the ball, I was on the starting five as a senior, but sixth man Sid was making a strong play for my spot. In the era before a shot clock, our strategy for the upcoming game against the league’s top team was to slow it down, just keep dribbling and passing out front, trying to keep the score close so a break at the end might fall in our favor.

Coach told me Sid was going to start in my place for that game because we needed his ball handling. That’s all he said. My interpretation of what he said was, “Norman, you’re a lousy ball handler.”

Consequently, when I did play in the game I was terrified of getting the ball and played poorly. Until then, as the team’s best shooter, I was all about having it in my hands.

I remember hearing my dad brag about my hard work when I split all the firewood piled in the backyard that would heat our house that winter. And my mom telling a friend that she didn’t really expect me to stick with the dreadful job of cleaning out cow stalls in the heat of summer after they had been unused and neglected for years. But I did.

I also remember Dad admonishing me for not wiping down the shower door in our one bathroom after he’d asked me to do it. When I told him I HAD done it, he pointed out a wet streak. I pointed out the rest of the shower, all dry, and said, “I wiped it down. I just missed a spot.”

When peach fuzz appeared on my cheeks, I used dad’s razor to scrape it off. After several months, he asked me if I was using his razor, because he’d noticed it not staying sharp as long. When I said, “Yes,” he asked, “Why? You don’t need to shave.”

“How would you know?” I asked him in one of the very few times I ever talked back to Dad. “I broke my glasses and held them together with white medical tape and it was two weeks before you noticed they were broken.” I saw hurt flit across his face.

I shot at some birds sitting on a telephone wire, not understanding the possible consequences of buckshot meeting wire. My grandpa Julius worked for the telephone company and it fell to him to come fix the line because the phones up and down the road weren’t working.

When he finished hours later, he came up to me and said it looked like someone shooting at birds had hit the wire. He paused, my heart hit my boots. Then he half-smiled, nodded, and went into the house to get a drink.

Of course, zillions of memories lurk in the crevices and canyons of my mind. Some can be called up instantly, others require the sharp impact like a boot to the brain when my ears snare some comment zipping randomly through time.

Whether we recall them clearly or not, the cumulative impact of comments positive and negative has a great deal of significance in shaping who we are. Remember that the next time your first reaction to a child’s silliness or clumsiness is to yell or say something hurtful.

It’s just words, but like an arrow they pierce. And like feathers from a busted pillow, you can never call them back.