Motivation and Desire: A New Way to Think About Why We do Everything and its Basis in Neuroscience

Some of our time is spent eating and drinking and some is spent on matters regarding reproduction. Some of us seek fame or recognition while others seek satisfaction internally, with little need for recognition. Some people study for success in a profession, while others might study rocks, birds, or French literature for no apparent reason other than to know about it. Why are we motivated to engage in so many apparently unrelated activities?