A very old and very wise Master once told me the fabled tale of when he was teaching his young padawan the subject of Mathematics.
Being a youngling who was particularly headstrong and who had supreme confidence in his own innate abilities, teaching the padawan soon became the most difficult task he had ever undertaken.
At the age of 5, on knowing all of his times tables the Padawan declared "I now know everything" and proceeded to display worrying and ugly signs of vanity; and so the Master took the decision to further the padawan's knowledge.
By the age of 13, on passing his GCSE mathematics exam with the highest possible grade, the young padawan once again declared to the listening world "NOW, I know everything" and once again the Master simply furthered the lessons and the youngling's knowledge.
At the age of 14 on passing "O"-level Mathematics the youngling made a similar declaration of his knowledge and the Master quietly continued his journey of understanding.
This cycle of teaching and learning continued through O/A-level, A-level, degree level, masters level, doctors level; and each time the padawan reached a new level of understanding he confidently declared how intelligent he was and how all encompassing his knowledge had now become, and each time the Master simply and quietly furthered the younger man's understanding.
And the moral of the story is......