The word "Duty" is very much imprinted on the lives of civilians. Behind that word, people waste their time and energy on things they don't want to do.
The son is grown up and on his way to giving his duty to his country. Mom and dad never bothered to bring him up, because the best upbringing is on the street. And if it doesn't help, you can always blame it on the bad teachers who didn't look after him. Why bother?