In "This Is Water," Wallace tells Kenyan graduates the fish story:
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?"
In Infinite Jest, one of the Crocodiles (long-time AA members) tells the fish story almost exactly as Wallace tells it:
“the wise old whiskery fish swims up to three young fish and goes, ‘Morning boys, how’s the water?’ and swims aware; and the three young fish… go, ‘What the fuck is water?’” (445)
One of the waters we're all in and mostly unaware of is language itself. In an interview with Larry McCaffery, Wallace discusses Ludwig Wittgenstein’s theory, emphasizing that “we’re in language" (144). In Infinite Jest, Lucien Antitoi is unaware of his embeddedness in language, and this unawareness proves fatal. Lucien “is one of the few natives of Notre Rai Pays ever who cannot understand French, just never caught on” (480), and yet he repeats the three French words he does know “to the broom in tones surprisingly gentle and kind for such a large terrorist” (483), indicating that even though he has no control over language, he is still embedded in it. The fact that “his mind is usually as clean and transparent as anything in the shop” (483) shows that Lucien is as unaware of his physical surroundings as he is of his linguistic embeddedness; he is "out of the sociolinguistic loop” (fn206, 1034). For Lucien, the undetectable water is language, and he cannot see it because it is as transparent as his mind.
This inability to communicate makes Lucien not only a fish unaware of the water, but a fish out of water altogether. Although he exists within a sea of language, he is ignorant of the rules and conventions of language and therefore cannot successfully communicate with others. Lucien may live in language, but he has no idea how to use language. Since the meaning of anything is determined by its use in a given context, Lucien effectively means nothing in the world, which is fundamentally a sea of language, where a meaningful existence is determined by an ability to communicate. His “lips are quivering not so much from fear – although there is certainly fear – but not from fear so much as in an attempt to form words. Words that are not and can never be words are sought by Lucien here through what he guesses to be the maxillofacial movements of speech, and there is a childlike pathos…” (488), which reiterates Lucien’s “childlike innocence” (480). Lucien goes through the same process a toddler would while trying to learn English, appropriating the right movements, trying to communicate. His inability to speak or understand makes him a landed-fish, out of his element because he is speechless. He wants to stop his attackers, but has a “pretty good intuition that the lone communicable ‘va chier, putain!’ wouldn’t be a good idea in this context” (fn206.1034), since that phrase would simply offend his assaulters.