The true capacity of a product is determined not by the user but the manufacture. The automobile was built with the capacity to travel 180mph; Therefore its full potential was determined by the manufacturer.
The true potential of the car was not affected by my opinion of its ability or by my previous experience with driving.
Whether or not i used the full capacity of the car's engine did not reduce its potential capacity.
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The same principle applies to your life. God created you like he did everything else, with the capacity to fulfill your purpose. 
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Therefore, your true capacity is not limited, reduced or altered by the opinion of others or your previous experience. You are capable of attaining the total aptitude given to you by your creator to fulfill his purpose for your life. Therefore, the key to maximimizing your full potential is to discover the purpose or reason for your life and commit to its fulfillment at all cost.