This wise old whiskery fish swims up to three young fish and goes, ‘Morning, boys, how’s the water?’ and swims away; and the three young fish watch him swim away and look at each other and go, ‘What the fuck is water?’ and swim away. The young biker leans back and smiles at Gately and gives an affable shrug and blatts away, a halter top’s tits mashed against his back.
As a tiny throw-away bit this fish-and-water joke sucks. But when expanded upon at length in DFW's Kenyon University grad speech it is overwhelmingly moving.