If I do something and let someone else take the blame, it's either cause me and the other person both know that I would truly be ****ed if I had to take the blame and that was just a favor the person was doing, or I didn't notice at the time that someone else was taking the blame for something and it was too small to really go back and apologize.
And then I go around living like I'm on the run. It's painful. Confession is a good, healthy thing. :)
When I was little it was really really painful for me, but then it goes away, you get used to it.