Your father, as the elder son, had the opportunity and the practice to help and care for his mother when growing up. His younger brother did not need to do those things, thus did not form the habit of thinking about caring and feeling good about it.
So, if you want your child to be like your father when you become old and infirm, refrain from doing everything for your child. Give him the chance to do by himself and have a sense of accomplishment. And insist that he help you out when you are performing a task and praise him for his efforts.
You want him to develop a reflex of feeling good after helping you out.
Of course, if you only need a card on your birthday, or a phone call on Christmas in that distant future, do everything for your child now so that he is and will be carefree.