You need some information, my dear fellow.

I live in the US and so I act accordingly. When I ride my bike on the boardwalk in my summer vacation town I don't wear a helmet. I ride gently on wood planks with no traffic in sight. It's light years from say, Manhattan streets. When I lived in Amsterdam many years ago I did not wear a helmet either, it's socially uncool and it's about the safest place to ride a bike.

Holland has the one of the safest traffic system in the world, including all traffic. The Dutch setup for bikes is extraordinarily well thought out. They have thousands of miles of bike paths, with traffic lights just for bikers; bikers get priority on most roads and drivers defer to bikers. It's Planet Bike.

You are more likely to get murdered in the US than to die in a biking accident in Holland.

Another factor is that most bike miles are utility trips, ordinary rides about town. The safety of biking this way comes out in this startling statistic. Less than 1% of bikers wear helmets in Holland, but 13 % of bikers injured wore helmets.

The pro-death faction will be quick to point out that this must mean that helmets are the cause of accidents, but there is a different explanation. Most biking accidents in Holland don't come from utility riders, but from sports biking, which involves substantially higher speeds, more risk-taking, and mountain biking. So as you up the pace, up goes the risk -- just like everywhere else.