Here's my example:
Todd had an appointment today at 10:30. It's thirty minutes away, so to be on time, he had to leave at 10. At 10:08, I looked at the clock and said, "You have to leave. Like, now!"
He thanked me for paying attention, and I apologized for not noticing it sooner and for making him late.
As he rushed out the door, he said again, "Thank you. I wasn't paying attention. The proper response to that is, 'you're welcome.' Love you."
I cried. I cried, because I really deep down believed it was my fault he was running late. I really deep down believed it was my responsibility to pay attention to the clock and make sure that he left on time. I really deep down believed, I deserved to be yelled at for not doing what I was supposed to. I really deep down believed that I was not good enough. I didn't anticipate his needs (without being naggy or controlling, because that is even worse than making him late...)
If I go deeper, I was afraid of being hurt for not doing what I was supposed to be doing. My failure creates intense fear. I know that wasn't there when I was a kid. As a kid, my failure might result in someone else getting hurt, but I wasn't afraid for my safety.
My safety became a fear by being in a marriage with someone who couldn't take responsibility for himself. He couldn't handle his own emotions, and I paid for that. I still cower in fear while also being unable to explain the fear.
This is not who I am, which means that with time, work, self-awareness, and whatever else it takes, I won't be afraid, and I won't feel like I have to apologize for something that isn't mine to apologize for.