I could give hundreds of examples of people who do and say inconsiderate things. Interestingly enough, it causes us to act ugly, rude, and inconsiderate as well. It is contagious!! Is this because we are just not thinking about what we are doing?
I know that no one likes to be taught how to parent their children. That is, until their children grow up to be dysfunctional or violent. Then they come running for help to try and undo the things they have done to cause their kids to act like angry and oppositional people.