“Success demands singleness of purpose.” – Vince Lombardi
Peter Pan represents the infinite number of possibilities of childhood, and by keeping all options open by remaining a boy he never dedicates to a path by consciously choosing to not pursue other adventures. He is stultified, the eternal child.
Does that sound like any “adults” you know?
To be a great long-distance runner you have to give up being a powerlifter and probably a great sprinter. Probably won’t be a rock star or Rembrandt either. Because there is only so much time in a day, so much energy in a person, and so many resources that need to be allocated. By spreading too thin, by choosing to be everything, ultimately you end up nothing.
Excellence demands focused effort. It requires sacrifice of less important things.