Question

why did gratiano says everyone should laugh in merchant of venice

Answer 1

Okay so gratiano is designed to be a comic character in MOV and is designed as a witty ( not so gentle) gentleman so he makes everyone laugh so that their lives are not dull like shylocks

Answer 2

Answer:

Gratiano has just told Antonio that he does not look well and that he is much too serious. He tells him that those who care too much about the world tend to lose the little they have. He says that Antonio does not look his old self.  

In reply, Antonio tells him that his vision of the world is just that - it is the world and nothing more. It is a stage on which every man plays a part and his one is a sad role.  

Gratiano suggests that if the world is as Antonio says, then he will play the part of a jester who will encourage laughter, causing faces to wrinkle. He would rather seek pleasure in wine and harm his liver than burden his heart with sad groans which could kill him.