Philosophically it is an interesting topic. Most of us will be on this earth 79 years according to statistics. The vast majority of us will come and go with little acknowledgement other than our families. Others, like Hawkings, Elvis, Sinatra, Michael Jackson etc left the world early, but will live on for generations in peoples minds and text books. Coleman is in great pain. I wouldn't change my life for his for any amount of money at this point.. but when I die, having lived a pretty decent life, no one other than my family and friends will remember my name. He on the other hand will live on for several generations in the annals of body building history.
Personally, I prefer my relatively mundane life if I can reach 79, relatively pain free and healthy, to his... but not everyone is that way. Some will risk it all to "go down in history"