Reactive people focus on circumstances over which they have no control. The negative energy generated by that focus, combined with neglect in areas they could do something about, causes their Circle of Influence to shrink. Proactive people focus their efforts on the things they can do something about. The nature of their energy is positive, enlarging and magnifying, causing their Circle of Influence to increase.
The 7 Habits of Highly Effective People Calendar, Stephen R. Covey, Friday, June 20, 2008