In 2005 the late American author David Foster Wallace gave a commencement speech to the graduating class at Kenyon College in Ohio. It began with one of those cute little stories you often hear in speeches to new graduates.
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?”