Its futile to wonder (or guess) what people will do and how they will react in a world where nobody knows what a zombie is. I mean think about it. Think of all that would have to be different in a world like that. No Thriller. No Cranberries. No "...of the Dead movies". This may seem like a small thing, but in alternate universes (because obviously that's what it is), small things like that can lead to enormous changes in behavior and culture. The lack of Thriller may have drastically altered the behavior patterns of the entire species. If you wake up from a coma, and see a bunch of zombies, dead people, cars on fire, and etc... you aren't going to ask someone what happened. You know what happened. Zombies came and fucked everything up. That's why zombies will never take over this world (while we still all have our memory, at least) Everyone here knows what a zombie is, how to stop one, and how to avoid one turning into a billion. Now a global endemic of memory loss is pretty much the only thing that would allow zombies a foothold here, which is why I will survive when everyone else is walking up to and poking zombies. You can erase my memory, but you can never erase my paranoia and reflexes. Or, if you want to wander around playing a guitar and yodeling like some kind of musical zombie buffet, you can go hang out with Pio during the Apocalypse.