Will the Real Me, Please Stand Up

You have this detailed image, a concept of who you are. You support it with a convenient set of memories of events which support your supposition. I am a decent, honest guy, trying to do the right thing, get through this life and hurt as few people as I can in the process. To continue believing that you also need to conveniently forget the times when you acted completely contrary to that carefully crafted image. You can think, for your entire life that you are one way and then in one defining moment, that glass house you have carefully built over the decades can be shattered. One day, you know who you are, everything is clear and you feel confident about your place in the universe; the next you are lost.