I can see where you are coming from, but I saw someone post here (and I don't know if this is true or not) that Zidane never meant to be a manager, and that he was preparing for an admin role at Real when he was given the job after Benitez got the sack. The rest is, as they say, history.
He's won the World Cup and EC for his national team, he's won the CL for Real and now he's won three straight CL titles as a manager. Not much left to do unless he wants a crack at the World Cup with France later on.