Your shadow self is all that is repressed, the subconscious, the right brain. To quote Carl Jung, "Everyone carries a shadow, and the less it is embodied in the individual's conscious life, the blacker and denser it is. At all counts, it forms an unconscious snag, thwarting our most well-meant intentions."
The alchemists of old also understood the need for balance. Their axiom was "As above, so below, as within, so without, so that the miracle of the one can be established."
So don't try too hard to be goody, goody. You'll sabatage that part of you. You must accept all that you are. Introspection is a valuable tool for self-knowledge. But too much introspection can be dull and counter productive. So play. Tag, you're it. Notice that which repels you in others. That is the dark part of your shadow showing through. Your shadow has tagged you. Notice that which attracts you in others. Again your shadow had tagged you. Making conscious choices, based on self knowledge is fine. But choices driven by repression may hurt us and others. Journaling can bring self knowledge, getting feedback from friends, reading our dreams. Those are good. But also know the brief flashes that come from jokes we like, the gut twinges we feel. The swift tags of our shadow. We can learn from all that. Learn to know the people we bring into our life. That's also the shadow at work, trying to bring about balance and wholeness. This is a game you can win.