Responsibility is something that every man, woman, even child must live with every day, for every step of their lives.
In the long run, we all, at some point, try to relieve ourselves of our responsibilities, and make up excuses to do so. But do these excuses make a difference in our long runs? Of course not!
So make sure that when you make your characters, make sure that they act the same, and have the same experiences with responsibility. And like those who are able to accept it, make them welcome their responsibilities and actually perform them.