Yes having a Black Belt in martial arts teaches you how to fight and defend yourself however a good black belt also knows how to avoid getting into fights if they can.
A good black belt also know and practices courtesy, loyalty, integrity, perseverance, self control, passion, empathy, compassion, generosity, love, inspiration, motivation, and so on and so forth.
Good black belts practice the life skills that not only improves their lives but also the lives of those around them.
To some this comes naturally, to others it must be taught. But for everyone it must be a daily practice of these good habits.
Strictly knowing how to fight and using those skills incorrectly does not make a person a black belt. They may have received one but are not one.
Black Belt is a state of being, not what is wrapped around your waist.
Master Jonathan Field