People who care too much about other people's opinions usually think that others are always targeting themselves ~ ~ ~ First of all, you should not take yourself too seriously. After all, they are ordinary people. Why do people want to target you alone? Don't be annoyed at your jokes, just smile. If you feel uncomfortable, punish him next time (not for narrow-minded people).

As for saying that someone speaks ill of others in front of you, it is normal. Who doesn't say good in front of everyone and who doesn't say good after everyone? Don't swear at him, don't contradict him, just listen. If you really think there is something wrong with the coach's personality, why not just change the gym?

In short, if you feel withdrawn and introverted, you can completely change it, but you must first get rid of your inner inferiority and unnecessary self-esteem (in fact, you are self-centered), and when you do this, you will gradually find yourself cheerful and lively ~ ~ ~