Sometimes the phenomenon is caused by fear. Fear not so much of the requirements, but rather the consequences of life as a hard target. Seriously protecting yourself calls for the annihilation of ties with society, ties that most people need the way they need oxygen. You give up friends, family, romance. You walk through the world like a ghost, detached from the living around you. If you were to die in, say, a bus accident, you’d wind up buried in an obscure municipal graveyard, just another John Doe, no flowers, no mourners, hell, no mourning. It’s natural, probably even desirable, to be afraid of all this.

Other times there’s a form of denial at work. Circuitous routes, extensive security checks, an ongoing internal dialogue consisting of If I were trying to get to me, how would I do it? all require a deep acceptance of the notion that there are people out there who have both the motive and the means to cut short your time on Earth. This notion is innately uncomfortable for the human psyche, so much so that it produces enormous stress even for soldiers in battle. A lot of guys, the first time they come under close-range fire, they’re shocked. “Why’s he trying to kill me?” they’re asking themselves. “What did I ever do to him?”

Think about it. Ever look in a closet or under the bed, when you’re alone in the house, to ensure that an intruder isn’t hiding there? Now, if you really believed that the Man in the Black Ski Mask was lurking in those places, would you behave the same way? Of course not. But it’s more comfortable to believe the danger only in the abstract, and to act on it only half-heartedly. That’s denial.

Finally, and most obviously, there is laziness. Who has the time or energy to inspect the family car for improvised explosive devices before every drive? Who can afford a two-hour, roundabout route to get to a place that could have been reached directly in ten minutes? Who wants to pass up a restaurant or bar just because the only seats available face the wall, not the entrance?