Great analogy to better understand marketing! Brian Tracy helped me also (click the link at about 6:30 min) with a very simple explanation what's the difference between marketing and selling and that goes so.. writing in my own words:

Imagine that i own a restaurant and i'm anywhere and ask the question: "Anybody here hungry?" and those who raise their hands.. that's marketing. Those are the prospects i'm identifying. Selling is if i convince someone to come to my restaurant rather than to someone elses.

Thank you!