Fear of Zombie Attack

I had to stop playing Fallout 3 because my zombie dreams were getting a lot worse than normal.

Now it's a lazy Sunday afternoon and I'm thinking about playing again. Having nightmares about a game is a good sign that I should stop playing.

My question is, what is the sign that is a good idea to start playing again?

Is it just that you don't think about zombies as much? Is it when you find yourself looking around your neighborhood picking out your post-apocalyptic sniper positions? Or is it like I'm saying "what's a good sign that you should start smoking again?"