Interesting article in the ny times:
http://www.nytimes.com/2013/01/29/scienc...130129&_r=0

a tiny risk mounts up if you take the risk daily.
The writer points out that at his age (75) people keep falling and hurting themselves. A shower may mean only a one in a thousand chance of a fall; but you have a daily shower over a thousand times in just 3 years....

> 'I first became aware of the New Guineans’ attitude toward risk on a trip into a forest when I proposed pitching our tents under a tree. my New Guinea friends absolutely refused. They explained that the tree was dead and might fall on us.

...I objected that it was so solid that it would be standing for many years. The New Guineans were unswayed..

In the following years..., I came to realize that every night that I camped in a New Guinea forest, I heard a tree falling. And when I did a frequency/risk calculation, I understood their point of view.

Consider: If you live in the forest and you adopt the habit of sleeping under dead trees whose odds of falling on you that particular night are only 1 in 1,000, you’ll be dead within a few years'
qjs.

The article makes a good point, and one that can be somewhat confusing to people.

The problem is that while the probability of the single event is low, when you do the math for a lot of events, the chance that it will happen at least once can be significant.

A simple example: a coin toss is 50/50. Now flip the coin say, 10 times. How often to you get all 10 results the same? Pretty rarely.

The one in a thousand event works the same; eventually, with enough tries, the chances of it happening to you, become significant.

And if the bad thing that happens is bad enough, it is totally rational to take extra precautions every time.

I think recognizing this is at the core of much of the attitude toward "prepping" of the folks on this forum: that unlikely events can and do occur almost daily (like the trees falling in the forest every night as described in the article). The odds of winning the local "million dollar" lotteries are 10's of millions to one. Yet, someone wins almost every week.

We all have decided that it is worthwhile to prepare for the unlikely event when and if it happens to us.

Isn't this the rationale that underlies a good many safety practices? - buckling your seat belt, wearing a helmet when cycling, checking the firearm for empty when you first pick it up, etc. When there is a likely very bad outcome, warding off low probability events makes good sense.

Absolutely. In fact, this philosophy is built into the safety training and safety culture on many industrial sites. I.e., it only takes one serious incident in a 30-year career to completely ruin your life, and it's impossible to know when that incident will occur; so you wear your gear and follow your safety practices every time.

Yes, and in my experience, it is one of the hardest ideas to get through to people. Just because they have gotten away with it 1000 times, does not mean it will not kill them on try 1001.