This question hits the nail on the head for me as I would like to think I have 'mastered' the art of mediation - though not yet, as I want to apply for a masters course in mediation next year. (Can't afford it this year). Maybe after the course I may be somewhere down the road to being a master of that profession.
Why would I like that? Practising mediation is a process i love doing as it gives me the opportunity to sit with people and help them reach an understanding that both find mutually satsifying. Helping them create the options to consider what will best serve their interests and needs is part of the challenge I enjoy.
Though somettimes I can feel overwhelmed and lost in the process, I have the techniques and skills to keep me on track. If and when I work with another mediator the 'mastery' of the other person can help me stay on track.
Maybe I'll have to stretch myself to doctorate to get the feeling of complete mastery, though I doubt that will really happen. Who knows? I want to try anyway.