He might have developed a reflex to leave a space

for you to fret about.

Or, he secretly enjoys the attention he is getting from you by provoking your reaction to his tardiness.

You need to quit worrying about his future and let him bear the consequences of his own action or inaction.

In your unconsciousness, you might have wished that he cares more about you. So, have him help you by telling him that you need his help. Then, when you are old and infirm, what drives him to visit is the reflex conditioned when he was young and happy to be your good helper.