Occasionally some owe their survival not to struggle, but to simple luck. Take the startling case of Mitsutaka Uchikoshi. One ice-cold October day in 2006, Uchikoshi had been at a party on a mountain in western Japan. After wandering off into a field on his own,Uchikoshi tripped, hit his head, and was knocked unconscious. As Uchikoshi remembers," I was in a field, and I felt very comfortable. That's my last memory". He remained unconscious in almost-freezing temperatures without food or water for more then three weeks