The quote by Milan Kundera in "The Joke" suggests that those who outwardly express their happiness and joy might be concealing deeper sadness within. This statement challenges the perception that vocal expressions of happiness are an indication of true contentment. Rather, it implies that the loudest declarations of joy can sometimes mask internal struggles or emotional pain.

This idea reflects a broader theme of duality in human emotions, where external appearances do not always align with internal feelings. It serves as a reminder that people might be dealing with significant issues beneath their cheerful facades, prompting a more compassionate understanding of others' experiences.