#Makesi Rocket said that the zombies actually were infected people, not dead people. So it's not like the dead are coming back to life or anything, it's an infection making people crazy. The fault with Romero's type of zombies is that if the zombies were slow to begin with, people would be able to escape them easily and nobody would become zombies. The zombies would quickly be exterminated by the military at the beginning of the apocalypse and everyone would carry on with their lives. Faster zombies would make much more sense.