Literature was born when a boy came crying wolf, wolf and there was no wolf behind him

He [Nabokov] has a point, and the point makes me think, but it does not give me the lightening flash of illumination that this does, a page or two later: 'Literature was born, not on the day a boy came crying wolf, wolf out of the Neanderthal valley with a big gray wolf at his heels: literature was born when a boy came crying wolf, wolf and there was no wolf behind him.'

S. Hill, Jacob's room is full of books (2017), 145
She is citing here Nabokov's Lectures on literature, which I now want to read