A strong body listens. It obeys. A weak body commands. If your body is weak it tells you what to do. If your body is strong it'll actually listen to you when you tell it to do something. If you build it right you can overcome some of the obstacles of age and recovery.
If you're ranked number one in the world it's because you've earned it, and I think the only way to really get there is to have that ability and to have it nurtured in a very competitive environment at an early age.
I suppose you could never say never, but my experience would tell me that the most successful players in the world are gonna come from an environment that is more competitive at an early age.