We use conscious mind when we knowingly think or do something. Something like working of our heart is not under conscious control. It is the power of the sub-conscious mind that makes our heart beat about 72 times per minute regularly for up to 100 years.
The sub-conscious mind is much more powerful than the conscious mind. But it is not under our direct control. It functions on the basis of information stored in it. It stores all kinds of information since the day the child is born. It even stores information that you are not consciously aware of. For example, a witness to an accident could not tell the car’s license plate number, but under hypnosis (hypnosis helps reach the sub-conscious) he gave the correct number.
Scientists had long believed that brain activity such as brain waves and secretion of brain chemicals were beyond conscious control. But, experiments on Swami Rama of the Himalayas and on biofeedback have now changed that belief. Now it is proven that some people can control their brain waves, etc.
To benefit from the unlimited power of your subconscious mind, I recommend Genius CD and my course Mind Power Exam Maximizer which gives many techniques, tricks, and builds skills to propel you ahead of others.