What makes a graduate student really happy?

Take a wild guess. No its not the promise of more money/less work from the advisor or an invitation from Europe for an all expense paid summer school. Its neither publishing something in some journal nor a job offer after graduation. If you are still wondering - its free food in any shape, size and variety. Starting from free coffee and cookies at weekly colloquium (even if one sleeps the whole hour and walks out not understanding a single word) to free pizza in Female Physics Forum meeting (who cares what happens there anyway) to the leftover food and wine in a conference - everything is equal in our eyes and quickly pounced upon. I wonder why departments don't realize that the easiest way to graduate students heart is through their mouth !