I wondered whether someone can live "with purpose" and yet have low stress. Previously I have explored the tradeoff between achievement and stress in my post Goal, Direction, or Journey?. But purpose and achievement are not identical: achievement is but one possible purpose. Purpose is simply something that you want to do; achievement suggests that you seek to do something that is challenging or new, at least to you. Achievement requires navigation of new territory of some kind, pushing boundaries, whether personal, intellectual, or socio-cultural. It usually involves setbacks and obstacles and therefore some frustration. In contrast, a purpose that is familiar and quotidian is much less likely to create stress than one that emphasizes achievement. In this case, one's life typically stays within known boundaries, and one's purpose is simply the daily living of that life.
Yet people differ in their response to familiarity. A recent article about ADHD and novelty-seeking behavior points out that certain people may be hardwired for variety, and get bored otherwise, which is its own form of stress. In combination with the fact that the people on isolated Greek islands probably have similar genetics, it is possible that eschewing achievement to reduce stress may or may not be successful for a particular individual. Perhaps being "Type A" is not a choice.
One can envision setting up an structure of achievement that involves habitual, familiar behaviors in the course of pursuing novel substance. Returning to an example from my earlier post, one could take photographs daily and attempt to improve during each of these sessions. This would quickly become habitual and familiar, yet would represent something more than living a static life. For those who have some need for achievement, who are wired for novelty yet wish to keep stress low, this is an improvement. Also, much depends on how one deals with setbacks and challenges - an overall countenance of lightness or detachment may mean that achievement can be pursued without undue stress.
Some aspects of activities, even if they happen regularly, will unavoidably cause stress. One is deadlines: they completely change the context of one's efforts and require that meeting the target be given priority over serenity. Another is confrontation: even the calmest monk will have an emotional reaction to an important disagreement with another person. Indeed even if the confrontation is habitual, as might be the case with a family member, it is likely to be a chronic source of stress. A few lone wolves in history have managed to find their life's work and achieve lasting results independent of external politics and timeframes, but this is extremely rare. Consequently, there may be a limit to what one can accomplish in a low stress environment; nevertheless, our brief explorations here suggest that by managing one's reactions and organizing one's activities appropriately, achievement and stress are not entirely and directly correlated. Thus, it is not a strict requirement to limit our purpose to the commonplace.