Although the reasons for which a person chooses to pursue a skill are complex, the fundamentals of the process of developing skills is extremely simple.
Skill development is nothing more than a continuous decision to respect the process of personality development. When we witness the end result, when we witness an act of excellence, when we witness the apex of development, we only see the performance. It is easy to overlook the way in which this achievement came into existence.
Because, today, we are bombarded from every direction with distractions and mechanisms of escape. When we are being called - or even forced - to embrace a mundane level of awareness, we cannot see the true, underlying, magnificence which the performer brings to us.
There is no substitution for awareness of the process. Without awareness of how skill development unfolds, there is no ability for an individual to push themselves into higher levels of achievement. The exception, of course, is children who do not have the biological capacity to be self-aware. They, instead, are completely at the mercy of their environments, and the directions their mentors and parents push them. Even during practice, a child is not aware of how or why they become better at what they do.
In contrast, an adult who seeks to develop a performance outside of their immediate survival needs must become self observant and introspective. People do not accumulate experience without becoming aware of - at the very least - the sacrifice of time that this requires.
Although it is also true that a person may become proficient in a skill without the desire to push, and without refining their development, the results come more slowly. The perfect example is an average student who, upon graduation, assumes the first postion which provides stability and meets their needs. Regardless of what this role is, and regardless of the level of ambition of this person, they will grow to understand the nuances of the work they do. They will become better at what they do. And, if given enough time, they will eventually achieve the highest level of mastery their developmental potential allows. However, the rate of progress will be slower in these cases, and such a person will not be capable of expanding into areas outside their own domain (unless they are forced to do so for economic reasons).
The primary factor which distinguishes an individual with high developmental potential is their self awareness, their ability to hone their own development. This factor is even more important than the powerful drive we often see in peak performers. Although drive and self awareness are complimentary developmental forces, many performers may not feel any sense of urgency as they develop mastery in a given field. This is especially true with individuals who are older and more experienced; once you are deeply aware of the process of development, and have attained its results, the sense of rush often fades.
Regardless, it is respect for the process of development which is key to building skill. A person does not attain mastery in any field without the dedication to make thousands of decisions in favor of skill development over other life experiences. A swimmer goes to bed early to wake for practice before work. An artist forgoes a typical career and lives a lifestyle which supports the honing of a craft. A doctor spends their twenties studying relentlessly instead of building a career or pursuing social activities.
In summary, a performer distinguishes themselves from the crowd by embracing, refining, and supporting a lifestyle which optimizes development of skill. Although other life opportunities will be presented, the performer relentlessly disregards them in preference for time with their craft, art, sport, profession, or other skill.