Often we judge ourselves too harshly, but that's no reason to stop doing it. Reflective thought or introspection are both nice ways of saying judge yourself and your behavior. This is how you change and grow. It's ok to recognize something about yourself or your life that you would like to change or improve. Same thing goes for admitting when you're wrong and being able to apologize when it's deserved.
This is certainly not to encourage being a door mat or to get down on yourself. Think of it this way, have you ever seen a person and, in a state of panic, asked do I look that; fat, old, bad in red, etc.? That's you taking the time to confirm you aren't doing exactly what you don't like on others. If you never stop and think about things you could be that woman that has the exact same hairdo she had 30 years ago.
Another example of this type of behavior is the person that re-writes history. I live in down town Portland next to an affluent high school. The kids are super annoying and they think they are SO cool. I can acknowledge that I was just as annoying at that age. I'm embarrassed, but it's true just the same. We see it all the time as we, and our peer group, get older. Someone gets dumped at the alter, 3 years later the story is it was a mutual decision. How awkward for the rest of us.
Admitting when you're wrong is not an easy thing to do. However, if you can never admit it people will probably tire of you. Can you really have a close friend that's never ever wrong? Who needs that?