Why doesn't the adopted son know his mother's hard work, and the adopted daughter knows his parents' good?

This sentence may mean that it is not easy for a woman to raise a son, because he doesn't have to have a child, so he will never understand the hardships of a woman raising a child. When a daughter gives birth to a child, she will realize that it is not easy for her mother to appreciate her kindness and repay her kindness. Besides, as the saying goes, a daughter is a mother's intimate little cotton-padded jacket, what's more, a man's heart is not as delicate as a woman's, and a woman will be more aware of her parents' difficulties after becoming a mother, so she will be more considerate of her parents.