And it brings up an interesting question: what does it mean to be the greatest? Is Muhammed Ali the best boxer of all time? Is he the best athlete of all time? Is he the best public sports figure ever? It's perhaps impossible to measure. Does he stack up against Honus Wagner, Babe Ruth, Michael Jordan, Jim Thorpe, or any of the other sports heroes? Is there even a way to measure "greatness" across sports and years?
I think what it comes down to is that he was the "greatest" in his sport, at his time, in his era. The "great" factor is better than all/many others not necessarily because of his talents or personality anymore, but the people that he touched as a culture. The reaction caused now is what's really the "greatest", not just a Rumble in the Jungle, or some poetic lines. I do wonder who we, my cotemporaries, will feel is the "greatest" when we're far older. We might be questioned the same way by the young people at the time.