So, let's say you live in a place that's in the "100 Year" flood plain.
That means you don't have to worry about a flood until 2108, right? WRONG.

You see, a 100 Year Flood does not mean every 100 years, there's a flood, it means that in any given year, your chances of having a monster flood is 1%.

It also means that each year you live in a place, you're increasingly at risk of experiencing the 1% event - in fact, if you live in the same place for 50 years, you have a 50% chance of experiencing a 100 yer flood (same goes for 25 years = 25%, etc. with the 100 year flood example)

So it is with this in mind that you need to do your situation and risk assessment profile. Are you preparing for unlikely risks?

For example, in 2003 about 45,000 Americans died in motor accidents out of population of 291,000,000. So, according to the National Safety Council this means your one-year odds of dying in a car accident is about one out of 6500. Therefore your lifetime probability (6500 ÷ about 78 years life expectancy) of dying in a motor accident are about one in 83. Gee, that's worth being prepared with a seatbelt and defensive driving classes.

But just how "equipped" do you need to be for a terrorist attack?

If terrorists were to destroy entirely one of America's 40,000 shopping malls per week, your chances of being there at the wrong time would be about one in one million or more. If terrorists hijacked and crashed one of America's 18,000 commercial flights per week that your chance of being on the crashed plane would be one in 135,000.

Even if terrorists were able to pull off one attack per year on the scale of 9/11 , that would mean your one-year risk would be one in 100,000 and your lifetime risk would be about one in 1300. (300,000,000 ÷ 3,000 = 100,000 ÷ 78 years = 1282) In other words, your risk of dying in a plausible terrorist attack is much lower than your risk of dying in a car accident, by walking across the street, by drowning, in a fire, by falling, or by being murdered.

You're at greater risk from your slippery bathroom floor than an earthquake, even if you live in California.

Always try to be rational. It will save you money and emotional wear and tear.