"We are different, in essence, from other men. If you want to win something, run 100 meters. If you want to experience something, run a marathon." Emil Zatopek
Zatopek was one who liked experiences and winning. In the 1952 Olympics he won both the 5,000 and 10,000m golds - and at the last minute he decided to run his first marathon as well. He got the gold medal in that too. As great as Bekele is - there is no way he could have won all three in Beijing. Part of that is how competitive all these races are these days - but, part of it is how incredible an accomplishment it was by Zatopek.
I'm not sure I completely trust his quote - because most of us who competed on any level ran long distance because we weren't fast enough for a more "sane" distance. But, the quote does illustrate why you have thousands of people lining up to run marathons - not 100 meter sprints. We are all looking for a unique experience. Something that is challenging and maybe even a little dangerous.