This is always bothered me about zombie movies

The only "zombie survival" universe I know of that includes prior knowledge of zombies is left 4 dead. To bad that's a video game

Maybe in some of those movies they do know what zombies are, but the idea of the dead is so horrifying that they try to explain the strange occurrences with excuses like rabies or crazy people to give themselves a false sense of security. BTW they should totally make a movie about Left 4 Dead!