You are not really happy. What is the joke told by MV Monster?

The monster said, "Are you really happy?"

The reason is:

1 about 3 minutes. MV "Are you really happy? Appears at the edge of the screen. Words. It means that everyone who has heard the joke is recalling the sentence just now and feels that he is not really happy, so his face has changed.

2. Those people laughed hypocritically after listening to it, because everyone was pretending, refusing to admit their inner pain and pretending that they were happy, so they laughed with the whole world and laughed together.

It's over ~~! !