What does it mean that people who think they are humble are humble, and those who think they are humble are promoted?

I was invited to dinner.

A man takes a seat, thinking he is humble and modest, and he is the last one to take a seat;

The second person also arrived, and the self-respecting person was interested and chose its first position.

When the host arrived, he respectfully asked someone to say, "Friends and distinguished guests are so humble, please sit down!" " So he reached into the first place to wake people up. A certain B is ashamed.