What did Dr. Warren mean when he said, "Rab played a man's part. Look that you do the same."
Rab was older than Johnny so he was more of a man than Johnny was.
One day Johnny would grow up and he, too, would be a man.
That Johnny should not cry, but move forward and do what needed to be done.
That Cilla would not want to marry Johnny one day because Rab was older, and already a man.