I think that there are three phrases civil people ought to know: please, thank you, and I'm sorry. I'm not too good at remembering the third one. You see, my parents tend to stress their intolerance of their children's imperfection over a desire to teach their children how to improve themselves. At least that’s the way it works at home, because even constructively criticizing someone in public is considered tactless to them for some reason.
Sometimes, I’m too scared to apologize after realizing I've done something wrong because I expect the affected party (usually my parents) to flare up from being reminded of how I've wronged them in the first place. What's the point in trying to make amends if the other person is just going to get enraged over my mistakes again?