When he was a child, Cosroes (later Cosroes I, King of Persia) had such a good master, that made him reach brilliant results in all the disciplines he tough him. One afternoon the master apparently reasonless punished him with hard severity.
Years later Cosroes ascended the throne. One of the first measures he took was order to bring his childhood master before him to require an explanation for the former injustice.
-Why did you punish me without deserving it? – asked him
-When I realize your intelligence, I knew immediately that one day you would ascend your father’s throne, - answered the master, – and wanted to show you how injustice can mark a man for the rest of his life. I hope you’ll never punish no one reasonless.