In this passage, the narrator expresses a mix of annoyance and humor about a character who seems to delight in knowing something the narrator doesn't. Despite the frustration, there is a playful tone, highlighting that the other person is well-versed in all things related to Parisian life.
The narrator, on the other hand, admits to having little knowledge, comparing their own understanding to that of a simple chocolate croissant. This contrast emphasizes the difference in experience and familiarity with Paris, setting up a dynamic of playful teasing and admiration between the characters.