I have pointed out before that this man was the only person to approach Jesus in honest fashion but to leave disappointed.
Although the overall point itself remains valid, perhaps I can argue against myself to an extent by considering the young man's attitude to The Commandments which he claimed 'to have fully kept since childhood'.
This suggests that the word 'ruler' of older translations would show that his origins were in a Pharisee family.
The Pharisee Tradition seemed sold on the idea of 'outward show' and Jesus needed to show this young chap that if he had 'kept the commandments' then it was not necessarily in the right spirit.In this there is a lesson for us all - Christianity is not all about keeping outer rules but has far more to do with what is in our hearts.