Why do online chats make jokes?

So if you know what you say will make people laugh, why do you have to tell others about your private affairs? Although we are friends, can you guarantee that your friends will not talk about you behind your back? As the saying goes, don't talk about your private affairs in front of anyone in the future, because others may laugh at you and look down on you, so some words can only rot in your stomach and don't tell anyone. For what has happened, then you don't have to worry about anything, because things have passed, let it pass forever, and pay attention to the way you speak in the future.