Current Events > Why is Max the only person that remembers the old world?

(+) Yeah! (+)

I finished Mad Max (the game) and everyone doesn't know what all the stuff from the old world is. Only Max can remember.

Now, as far as I remember from the movies, they never really showed what happened, but the game kind of hints that it's some sort of disease. So the only explanation I can think of is that Max is immune from the disease and everyone else that was got wiped out?