Despite all the motivational factors attributing to our human race's momentum, there is one word to sum up all drives. That word is satisfaction.

whether you are after money, cars, women, men, peace, a new eraser for your pencil, we all seek to gain satisfaction from our activities. Some may dispute that even though a person may want something, they make no discernable effort to gain it, therefore could not be seeking true satisfaction. However, if that were the case, said person's goal would not be that thing, but rather the wanting of that thing. For some, that would be enough. I wish I could be so easily satisfied.

If you take satisfaction to the next level however, you find that stimulation on the cellular level is what satisfaction is all about.  Each one of your cells is covered with receptors.  Each receptor is designed to recieve a particular peptide which is produced within the brain. 

The interesting thing about the receptor/peptide relationship is that it is programmable.  In the case of addictions, hobbies and routine, cells will generate more receptors for a particular peptide, such as a sex stimulated peptide or a food enduced peptide. These receptors are governed by our emotions. It is for this reason that things like positive reinforcement and self afirmation have a place in science, though the feild is still being explored.  For many, altering ones receptor count can be as simple as a morning mantra or a routine activity.   

The downside however is, that a cell only has room for so many receptors.  As you generate more for a particular action or feeling, you reduce the number of receptors for things like nutrients.  That being said, we should be careful about the level of stimulation we participate in.  It is easy to see why many zen masters and monks strive to find a balance. 

Scott