"Greasy Lake" is an exploration of the author's own experiences growing up in the 1950s and 60s, examining the youth culture of the time and the gap between teenage certainty and adult reality. In the opening paragraph, the narrator speaks about the allure of appearing "bad," of having no respect for laws and society, and about rebelling against the norm.
We wore torn-up leather jackets, slouched around with toothpicks in our mouths... We drank gin and grape juice, Tango, Thunderbird, and Bali Hai. We were nineteen. We were bad. We read Andre Gide and struck elaborate poses to show that we didn't [care] about anything. At night, we went up to Greasy Lake.
(Boyle, "Greasy Lake," teacherweb.com)
Their choice of André Gide, Nobel Prize-winning author, can be read as an attempt to appear worldly without actually understanding the text. This is typical counterculture behavior; deliberately seeking out and reading an obscure or inaccessible work sets the boys apart from society, showing them to be different without the hard work of interpreting and applying Gide's philosophies.
Like the leather jackets, the toothpicks, and the Thunderbird (a cheap fortified wine), the teenagers use the philosophical work as an affectation, a symbol of their disaffection from society and their supposedly inherent badness. "We don't need the 'normal' societal works of literature," they seem to say. "Look at how strange and different we are! We read obscure philosophy!" In this sense, Gide himself is not the important aspect; rather, the use of his name (like Kant, Kafka, or Kerouac) instills a sense of otherness, to differentiate themselves from "the squares" and create a personal, immature sense of self.