Mastery requires a time horizon that most people have never seriously held in mind. Not months, not a year — ten years. The figure is not arbitrary. It appears repeatedly in the empirical literature on expert performance, in retrospective accounts of practitioners who have reached genuine depth in their field, and in historical analyses of creative and technical careers. Ten years of sustained, deliberate engagement with a domain is roughly what it takes to move from competent to genuinely masterful — not because the domain is infinitely complex, but because the kind of learning that produces mastery is slow, non-linear, and requires a density of experience that cannot be compressed without loss.
Most people's career planning does not operate at this horizon. It operates at months to a few years — the next performance review, the next promotion, the next opportunity that comes available. There is nothing wrong with this as tactical planning, but it is a different activity from the development of mastery, and if tactical planning is all there is, mastery will not accumulate. The ten-year horizon requires a separate, deliberate decision: I am going to develop genuine depth in this domain, and I am going to organize a significant portion of my learning and practice around that goal, with the understanding that the return on this investment will not be visible for years.
The psychological difficulty of this commitment is real. The cultural environment is saturated with messages about rapid achievement: skills developed quickly, career inflection points reached early, disruption of traditional timelines. Some of this is real — certain skills can be developed quickly with focused deliberate practice — but genuine mastery of a complex domain is not among them. The people who appear to have achieved mastery rapidly have typically not achieved it rapidly; they have achieved visibility rapidly, or they have reached competence rapidly in a domain that does not actually require mastery to perform publicly. The mastery of surgeons, structural engineers, experienced therapists, and deep-domain specialists is not developed in months; it is deposited in years.
Robert Greene's framing in Mastery is useful here: he describes the period of deep immersion in a domain as an "apprenticeship phase" that most people in contemporary working life try to skip. They want to arrive at the position of master without the period of sustained subordination, deliberate practice, and patient accumulation that produces it. The skipping does not work, and the result is people operating at the level of surface competence who mistake it for depth.
The ten-year horizon changes the daily practice. When you are operating with this horizon in mind, the question you ask about your work is not "am I performing adequately?" but "am I getting better?" The difference is the presence of a developmental vector — a direction of movement over time that is distinct from the performance of current competence. The development of mastery is not the same as the performance of existing skill. It requires deliberately seeking the edges of your current capacity, accepting the discomfort of operating at those edges, and sustaining the effort long enough for the accumulation to become apparent.