Buster Posey's parents tell the story about the one attempt their son made to free himself from his nickname. He was very young, in elementary school, and Gerald Dempsey Posey III informed his folks he no longer wanted to be called Buster.
The response was, in summation: Well, that's what we call you. That's your name.
That the boy simply moved on and never raised the issue again was probably some early insight into his tendency to keep everything in perspective, to recognize what he can or can't control and what's actually important.