Whether it be eating, drinking, reading, talking, sleeping or meditating, our being yearns to completely experience every activity that we engage in and be fully involved in it. Are we fully conscious of every action we engage in? Are we aware every moment of our lives?
A small story:
A man was traveling by cab to the airport. The cabbie was driving very fast, zipping around corners and sharp turns. The passenger was getting terrified. Finally, the cab driver, seeing the terrified passenger, said, "Why don't you do what I do when I take turns? Just shut your eyes!"
When you are not completely aware and involved in the action you are engaged in, your being remains unfulfilled in that experience. The unfulfilled experience remains inside you and keeps pulling you to repeat the action with intensity to fulfill itself. This is karma. Karma is the collection of unfulfilled experiences that stay in us and constantly pull us to fulfill them.
Anything that we do and experience intensely and deeply will always leave our system. It will liberate us. Any experience that we did not go through completely, through which we did not have complete fulfillment, which did not get our full energy, attention and awareness, remains inside us as karma.
Even though we carry some karma, basically we are complete fulfillment, wholeness. So any karma that has not been fulfilled cannot rest inside us too long. It will try its best to fulfill itself. It will drive us again and again to go through the same activity so that it can be fulfilled. Any desire, any experience, which has not become complete in our system will remain as karma and push us again and again to go through the same experience.
Our own thoughts, words and deeds become our karma and drive us to reach fulfillment in some way. This is the essence of the karma theory: the totality of all your past is the present, and the totality of your present is your future.
In any given moment, the future is predestined — but conditionally. It will be a certain future according to all the totality of events till that time — this is the predestined future. But it is conditional. There is an important factor that can and will change it — your consciousness, your will. Destiny is not something written in stone. It very much depends on how you choose to respond to every situation life presents to you. Your awareness will give you the intelligence and the courage to change the flow of events in your life.