Why do people tell unintentional lies??

If you don't understand by the above said question, let me explain in a very simple way. It's lies people tell in order not to dissapoint, angered, saddened, etc....some other people be it our grandparents, parents, siblings, friends, children, employer, employees, etc........

The most common one is between children and their parents. Why do children do this? I personally don't think or feel that they do it on purpose. Maybe there are a handful who does it intentionally but i also believe there are children who are "force" to tell their parents this unintentional lies. This is because whenever they tell the truth, their parents will scold them or fully disagree with them. Thus in time, they are more confortable telling lies to their parents so their parents will not get dissaponted in any way. Come to think of it, i feels that parents should sometimes allow their children to explain themselves rather than shouting or showing faces at them at everything they do. What do you all think? Anyone who have a better explanation for this?

Sometimes i really think what is right for us to do. Of course it is right to tell the truth but then when we tell the truth, we will be wronged and if we tell lies, people tend to believe what we said. So in conclusion, everyone will eventually tell lies. Am i not right??