We've seen a lot of zombie movies: Night of the Living Dead, Dawn of the Dead, Shaun of the Dead, The Walking Dead. Lots of dead, and lots of dead. One thing never crossed out minds—what would happen if we started making out with a zombie? That's exactly what Julie thinks in Warm Bodies, and it ends up saving the day.
When they kiss, R fights his zombie nature to devour her, "and something happens. It changes. […] it becomes something altogether different. Something new" (2.8.179). And then Julie turns into some sort of necrophiliac superwoman with golden eyes. (We did not make that up.) Just her mere existence starts curing zombies of their bad cases of the blahs.
So, when zombies attack, get out your lipstick not your shotgun. We'll be waiting over there behind all the guys with guns, and we'll see how that works out for you.