Extreme Sleeping

While living in Japan, I was amazed at the Japanese people's ability to fall asleep extremely quickly almost anywhere. It was also a source of frustration when two of my wonderful students visited and they would fall asleep while I was driving them around sightseeing. This is a great site where someone has photographed various sleeping souls in Japan. It focuses on the salary man but you can see many others also sleeping in the pictures. I wish I understood why and how they can do it.