2. You have accumulated a stockpile of weapons, ammuntions, clean water and food just in case.
I know you're just joking, but this one is true for me, and has nothing to do with any computer games...
I've kept hundreds of rounds of ammo, a couple weapons, a couple gallons of water (two drops of Clorox per gallon will keep the water fresh for years), and enough food that doesn't need to be cooked to last about a month if properly rationed, for pretty much all of my life.
I can remember having the Civil Defense drills in school. They would set off the air horns that could be heard for about a 20 mile radius, and everyone would have to "duck and cover" under their desks. Anyone that was a kid during the cold war will remember them too. After a couple years of this sort of conditioning, some folks (like myself) begin to live with the attitude that "it's better to have and not need, than to need and not have".
Keeping a water and food stockpile has actually paid off once. It was in the aftermath of Hurricane Hugo in '89. I'll admit, it wasn't as bad as it was in New Orleans after Katrina in '05, but both events only reinforced my behavioral pattern.