He got actually hit twice, once when he received the scar, and a 2nd time when voldemort attempts to kill harry in the forbidden forest and destroys the accidental horcrux. But it is cast at him many other times- 1.) In the Graveyard Duel by Voldemort, but Priori Incantem and his own disarming charm save him. 2.) In the Department of Mysteries again by Voldemort, but Dumbledore comes in in time and blocks it. 3.) When he comes back from the horcrux limbo, and Voldemort again casts it, but because Harry's the master of the elder wand, it rebounds and kills Voldemort once and for all.