My journey to understand the nature of fear began in 1986, in Kenya. After spending a month studying monkey behavior in Kakamega National Park, a spectacular remnant of the West African rain forests, I took a train to Nairobi, then to Mombasa, and started the first long leg of a cycling trip. My mountain bike was overloaded. A sleeping bag was secured to the top of the rear rack and a tent tied to the top of the front rack. My bike was wobbly and the road was bumpy, so I straddled the line between tarmac and sandy roadside as I cycled toward Tanzania. Unlike the trans-African highway or streets around Nairobi, this road felt reasonably safe. There was little traffic. Periodically, a heavily laden lorry or an occasional bus passed by, belching black diesel exhaust.
Late in the afternoon I was pedaling slowly up a long, straight hill at ...
