Explain this symbol--please.

Near the end of the film after Lateef learns that the Hazara girl will be moving back to Bamian, he is stunned. He stands near a pool of water and takes off his cap, leaving it and the hair pin that belonged to Baran that he'd attached to it lying on the edge. Is the cap a sign of his youth--adult men don't seem to be wearing caps; and is his leaving it a sign of his having become a man?