One must be drenched in words, literally soaked in them, to have the right ones form themselves into the proper patterns at the right moment.
Correction does much, but encouragement does more.
Encouragement after censure is as the sun after a shower. Humor him by all means, draw it all out, and hold him to it. A Friend may well be reckoned the masterpiece of Nature. The purpose of computing is insight, not numbers. The difficult part in an argument is not to defend one's opinion, but rather to know it.