I also have it but haven't cracked it in a long time. Maybe I should because I didn't remember the writing style. The glorious B&W illustrations are very helpful.

I took a couple of teen trips with American Youth Hostels in summer of 1975. AYH had just started selling helmets, and they had just come on the market. They had the Bell Biker and also an MSR helmet designed for spelunking. The description said that it was hotter than the Bell. And the Bell was quite hot. I got myself a Bell in about 1979. People ridiculed me for wearing it, as it was quite unusual. My college girlfriend had a spill on her bike, and she apologized for ridiculing me and bought a helmet. In 1982, I had a horrific crash, as I was hit head-on by a car. I don't remember the crash or the ambulance ride. My memory is "turn left, wake up in the hospital in great pain." My Biker helmet was scratched and crushed, having done its job. The doctor who woke me up had witnessed the thing and said I flew 50 feet in the air. Thinking about that, I'm not sure I believe him, but that's what he said. If it's true, it's amazing how well I fared. I was scratched and bruised and nothing else. My bike was mangled so I guess my bike and helmet did a great job protecting me.