Someone is laughing behind my back, not once or twice. What should I do?

First of all, you should face up to yourself and treat others correctly. If the people who talk about you behind your back are not important to you, there is no need to care about them. You can automatically block them and don't let them affect your opinion of yourself. After all, the strong never care about some scum, but only shut them up with more dazzling achievements. So you can ignore their ridicule and comments first, then try to be yourself and prove everything with your own achievements. Finally, you can secretly record their comments or laugh at your recordings, find them to play them, and add that "your level can only do these vulgar things." If you think your people have a good relationship, I think you can communicate directly face to face and tell them that you prefer to give advice face to face rather than talk about your affairs behind your back. If they don't pay attention, you can give up interacting with them. Finally, I hope you can be brave and face up to your behavior. After all, "I save myself three times a day"?