For me, I think it is mainly the psychological that causes the symptoms of "maturity leading to aches and pains" to vanish. The freedom to live fully here feels so much greater than in the States ( in my opinion), my activity level is higher here and the over all happiness I experience here drops my blood pressure, relieves most aches and pains, and brightens my mental outlook enormously! Living here may not be the "Fountain of Youth", but it has made a dramatic difference in my feeling of general well-being. Isn't that what all of us expats hope for in our retirement?

