Being aware of what is happening in and around oneself enables optimal performance. Optimal performance is getting what you want to get done in the most effective way.
The kind of awareness we are interested in is not a reflection on what has happened after it has happened. It is bare-awareness, a simultaneous knowing that allows the natural flow of effective action. Mindfulness practice is a method to cultivate bare-awareness.
Does Mindfulness Get in the Way?
Mindfulness practitioners make an effort to cultivate and enhance their own mindfulness. As their practice matures, they experience the development of witness - a natural aspect of mind that observes. It is this aspect of mind that develops into bare-awareness.