He knows he can't have everything his own way every time. He knows when to compromise and is not too proud to do it. Maturity is humility. Maturity is the ability to live up to your responsibilities, and this means being dependable. It means keeping your word.
Dependability is the hallmark of integrity.
Unfortunately, the world is filled with people who can't be counted on. When you need them most, they are among the missing. They break promises and substitute alibis for performance. They show up late or not at all. They are confused and disorganized.