Making excuses ~

I wonder if it is a nature for people to run away from mistakes, run away from admitting they did something not rightful? In the other side, people will always boast how well they did ... I wonder if it is a nature for people to make excuses to cover up their ass in the sake of doesnt want to admit that they did wrongly. Why it has to be in this way? Well, never admitting mistakes is one thing, the most funny thing is, people who make excuses and try to push the responsibilities to another person without feeling guilty... this is indeed a very very high tactic .. haha ... I wonder if this is about how we being brought up since a child....