Here is a practical definition of self-awareness: The process of gaining understanding of who you are and how your emotions, thoughts, and behaviors affect you and others.
A lot of people think that self-awareness is something negative or scary that will force them to face things they don't want to. That perspective in itself indicates a lack of understanding of how important it is to be able to look at yourself so you can live consciously instead of repeating the mistakes of the past.
Proactive, forward-thinking people use self-awareness as a tool to treat themselves and others well rather than living in perpetual inner and outer discomfort or conflict. Remember, life is so much more enjoyable and fulfilling when you experience it wide awake.