It's good to express confidence in someone.
Andy is listening to his son Evan tell him what he wants to be when he grows up.
Andy wants to be a good parent.
Andy tells Evan he can accomplish anything he sets his mind to if he works hard.
Andy tells his son Evan to give up his dreams and do something more practical.
Evan pursues his dreams and increases his self-esteem.
Evan loses confidence in himself and his dreams and never fulfills his potential.