Enthusiasm

"No one keeps up his enthusiasm automatically.  Enthusiasm must be nourished with new actions, new aspirations, new efforts, new vision.  Compete with yourself; set your teeth and dive into the job of breaking your own record.  It is one's own fault if his enthusiasm is gone; he has failed to feed it."

-Edwin Way Teale

I have obviously failed to feed my enthusiasm. But the question is, "What does enthusiasm eat?" I need to find how and what to feed it or else languish in this sea of blah forever!