Anecdote time. I was working at a job and I had been trying really hard for a promotion. When my employee review came up my boss said to me "You have a really strong personality and a lot of people find that very intimidating." I was shocked into a momentary silence. I didn't have a strong personality - she was crazy! I was a doormat. Except, the more that I thought about it the more I came to realize that I wasn't a doormat. Easy-going a lot, but not a doormat.
So why did I think this? Well, it turns out that I had surrounded myself with such strong personalities - much stronger than my own - that I never realized just what kind of person I was. Compared to those people I could have been a doormat, but to the average person I was not.
It was actually that incident that got me thinking about the lies we tell ourselves about ourselves. From the simple (I'm ugly, I'm stupid etc) to the more complex (Well I can't because..). I created the person I thought I was. I living in the illusion of an image of myself. I had to break free of those before I could be honest with myself about how I was and who I wanted to be. Sometimes I still find myself telling lines about who I am.
When I do my inventories to find where I have failed myself I need to be sure that the image of myself is a true one. To find those faults I cannot lie to myself about how bad they really are or if they actually exist. It goes back to be honest with myself and not excusing my behaviors. I know now that when I start making an excuse for my behavior it's time to take a closer look at myself. Chances are I am trying to hide an aspect of my own personality from myself.
It's hard to do because your illusion can be made to ignore a fault or to enlarge it. The good news is, that illusion often does not hold up to a close and honest inspection. So that is where every good introspection must begin.