Ingratitude denotes spiritual immaturity. Infants do not always appreciate what parents do for them. They have short memories. Their concern is not what you did for me yesterday, but what are you doing for me today. The past is meaningless and so is the future. They live for the present.
Those who are mature are deeply appreciative of those who labored in the past. They recognize those who labor during the present and provide for those who will be laboring in the future.