Excellent article. I have only one disappointment, which is that the commenters offered none of their own apology moments. But I will offer some of mine.
I am 76, so the list of things I regret and would apologize for if given the chance are too many to list. I have spent a lot of time in my old age writing to, speaking with and apologizing to people I feel I have abused or demeaned in some way. Usually, they say they don't know what I'm talking about, but I know. I don't do it to feel better, and I usually don't. It's just the thing you do.
I coached basketball for close to 30 years. Met and grew close to many kids (and sometimes their parents). I loved those kids and would do anything for them. But I also know that, except for the last few years, I was a very intense coach and was often focused so much on the win that I did not notice things going on with the kids. That intensity also made me an intense father with my oldest son (who was always the star), pushing him to college ball when that is not what he wanted. I didn't get it until he dropped out of the sport altogether because he couldn't take the pressure of that world, and I 've been apologizing to him ever since.
I have never regretted apologizing to anyone, regardless of their reaction. I also think that's why my marriage of 38 years has survived.