Why do people who show off become annoying?

People who love to show off are overly vain. Such people will suffer the pain brought by vanity throughout their lives, because although they appear fat on the outside, they are empty inside. The vanity on the surface and the emptiness deep inside are always in constant struggle. On the one hand, they are tortured by their unsatisfactory status quo before they achieve their goals. On the other hand, even after they achieve their goals, they are afraid that the truth will be exposed, so they The soul is always painful, and there is no happiness in their lives.