Hypochondria

Hypochondria is the only thing that will really help you to stay alive. But, the difference now that there are zombies as opposed to before is that your hypochondria should be directed at every other human around you. Did you hear someone cough? Was that blood she just spit out? Why is he itching his arm? He's been itching his arm for an hour now. Why the FUCK is he itching his arm?! You should constantly examine your fellow survivors secretly for signs of having been bitten and use these extraordinary circumstances to justify the one thing you've always wanted to do: shoot now and ask questions never.

Every now and then you'll come across an old magazine or newspaper that will mention AIDS. You should take a moment to think about how you no longer care even a little bit about AIDS. In fact, AIDS should now seem like a welcome break. The thought of dying in 10 years should seem like a beautiful pipe dream. Cancer, Hepatitis, Ebola, SARS, Swine Flu, MRSA -- you can now say all these words out loud, write them down, and even imagine what it would be like to have them without even breaking a sweat. You could even hold hands with a bunch of harlequin babies while they gurgled the national anthem without throwing up. Things are so much different now...

Even though you know it takes less than a day for a person who's been bitten to turn into a zombie, you should submit to the wiles of your hypochondria anyway. If anyone in your group comes anywhere near a zombie, or is splattered at all with any bit of zombie goo, you should keep a keenly suspicious eye on him for pretty much the rest of his (or your) life. This general suspicion you'll start to harbor towards pretty much everyone should cause you to provoke unnecessary fights with people and raise the sensation of anxiety in your bunker to absolutely frenetic levels. To aid in this, you should also start to say things like "Hey...I've got my eye on you," while gesturing menacingly at your own eye.  

It's important to not connect the facts in your head that every single zombie attack you've seen so far that has resulted in someone becoming a zombie has taken less than a day and the person became almost immediately bed-ridden after the exposure. Because this will be the one time that it takes several days instead of several hours and the person will exhibit no warning signs. This will be the one time where someone will become a zombie inside your bunker and eat you while you're asleep. This will be the one time it's not in your head.