His father took him into his study and said, "I'll make a deal with you. You bring your grades up, study your Talmud a little, get your hair cut and then we'll talk about it."
After about a month, the boy came back and again asked his father if they could discuss his use of the car. They again went into the father's study where the father said, "Son, I've been very proud of you. You have brought your grades up, you've studied the Talmud diligently, but you didn't get your hair cut."
The young man waited a moment and then replied, "You know Dad, I've been thinking about that. You know Samson had long hair, Moses had long hair, Noah had long hair, and even Jesus had long hair."
The rabbi said, "Yes, and they walked everywhere they went."