I like to use a little story I call "The Buffet". I will tell this story right after lunch on the first day of class. I like to start by asking the class if they had a good lunch. Then I start talking about how much I like going to a buffet for lunch because I get to eat as much as I like. In short, the story goes on about how I can never leave the buffet without overeating because I want to get my money's worth. I then relate that information to the school and how we are a buffet of knowledge. I tell them "It's your money, you paid for the buffet, it's time to overeat, grab a second plate."