There is a famous saying, "When you laugh, the whole world laughs with you; when you cry, you are the only one in the world crying". Who said that? What do you mean?
This is an old western proverb, and its specific meaning has not been verified. This means that each of us is the source of happiness. While giving happiness to others, we also get happiness from others, but the pain is only yourself. You can't put your own pain on others, so we should try not to suffer in this world, but to live happily every day.