Denial is listed as an immature developmental defense along with delusion, distortion and projection in the Diagnostic and Statistical Manual IV of the American Psychiatric Association. People who are not open to hearing information and criticism about themselves can become Masters of Denial. There is no end to what they can make themselves believe for their own benefit.
One man who identified himself as an ex-abuser describes it this way in his article The Three Horsemen of Denial. Here are the three main ways we lie to ourselves:
We minimize the damage we’ve done
We rationalize our actions
We justify ourselves in doing them.