When is it hard to Apologize?

My dad never apologizes for anything. He doesn't apologize when he's actually wrong. He doesn't even apologize to look good. He just doesn't apologize, period. He can be sorry in his mind and know he is wrong in his heart, but he has never spoke, whispered, stuttered the word "sorry." It's hard for me to apologize to him, if he never apologizes for anything.

When I do something subtly wrong in front of everyone, it's hard to come back and apologize. I could just let it pass, and that would be over with. No need to go back and be sorry for something I meant to keep under control. But I should, and I know it, and it's hard to apologize right then.

And it's very hard to apologize when I don't need to, when I know I didn't do anything wrong. Furthermore, it's harder to apologize when I know I'm right, but I have to apologize anyway, because that's just the way things are.