2016 High school and college commencement came and gone. Here is commencemtn speech given by Wallace at Kenyon College in 2005.
This is Water
There are these two young fish swimming along, and they happen to meet an older fish swimming the other way, who nods at them and says, "Morning, boys, how's the water?" And the two young fish swim on for a bit, and then eventually one of them looks over at the other and goes, "What the hell is water?"
Here is the complete text of the sppech http://bulletin.kenyon.edu/x4280.html