In a piece for the New Yorker, John Updike described how Calvino "manages to charm and entertain the reader in the teeth of a scheme designed to frustrate all reasonable readerly expectations" (source). In other words, it's mostly Calvino's tone that allows him to get away with what he's doing in this book.
Our guys is conversational, intimate, and playful—but also deeply philosophical. In fact, there are certain passages in this book where you can actually see all four elements working at once. Take this mesmerizing opening passage, for example:
Relax. Concentrate. Dispel every other thought. Let the world around you fade. Best to close the door; the TV is always on in the next room. Tell the others right away, "No, I don't want to watch TV!" Raise your voice— (1.1).
Quite frankly, Calvino really needs to be as charming as he can, because if he weren't, most readers would never let him get away with messing with their brains so much.
Calvino understands that if you want to change the way people think, you can't just get in their faces and shout like Lotaria. You need to give them something new to enjoy, and open them up to all the pleasure they could experience if they'd change their thinking. Right away, he makes you feel great about the fact that you've sat down to read, and then he throws in some humor to make you feel like his ally. During his time, Calvino knew that TV was going to make it hard for books to survive, and this no doubt motivated him to find new ways of making books fresh and enjoyable.
Make no mistake, our author is trying to challenge your assumptions as a reader; but his witty, charming tone shows that he's also willing to do what it takes to get you on board with his way of thinking.