I have always been fascinated by individuals who become the "best in the world" at something that is extremely competitive. Do they have more talent than others? More drive? Better coaching or teaching? Did they start younger? Did they have more luck? Did they have a particular mentor who helped them? Did they have to overcome obstacles? Did they learn from mistakes more than others do? Were their physical gifts matched by intellectual gifts? Why them? (And, implicitly, why not me?)
There are only a few people who fit this description at any given time. In sports, right now, I'd say Rafael Nadal in tennis, LeBron James in basketball, Albert Pujols in baseball, Lionel Messi in soccer. (A few years ago, it would have been names like Federer, Kobe, A-Rod.) Only a year ago you would have said Tiger Woods in golf, but no more.
In the world of the arts the determinations are harder -- acting is subjective, popular music is diffuse, creative writing (novels) is personal and not truly competitive, etc. One area where there has been a consensus has been in the world of opera, where there have been only a few tenors who gain serious notice as the "greatest tenor in the world."
Anyway, two men who have been the greatest in the world at different times have their birthdays today. Jack Nicklaus turns 70. Nicklaus is the greatest golfer ever. Woods had a chance to eclipse him, and may still do so, but my prediction is that Woods is done, and won't pass Nicklaus' total of 18 major championships. Woods is at 14 now, so he would need to have what for anyone else would be considered a fantastic career (5 majors) just to pass him, starting now, at age 34, with his confidence shot and bum knees. Not going to happen.
Here is Nicklaus winning his last major, the 1986 Masters, at the age of 46:
Another "greatest in the world" whose birthday is today is the great tenor Placido Domingo, who turns 69. Here is Domingo singing the great aria "Nessun Dorma" from Puccini's opera, Turandot:
On a more minor key, today is the birthday of the literary critic, Louis Menand, whose book The Metaphysical Club, is one of the more interesting books on the "history of ideas" in America that I've read. He's 58.