"We observe old people and see them age, so we associate aging with their loss of muscle mass, bone weakness, loss of mental function, taste for Frank Sinatra music, and similar degenerative effects. But these failures to self-repair come largely from maladjustment--either too few stressors or too little time for recovery between them--and maladjustment for this author is the mismatch between one's design and the structure of the randomness of the environment (what I call more technically its "distributional or statistical properties"). What we observe in "aging" is a combination of maladjustment and senescence, and it appears that the two are separable--senescence might not be avoidable, and should not be avoided (it would contradict the logic of life, as we will see in the next chapter); maladjustment is avoidable. Much of aging comes from a misunderstanding of the effect of comfort--a disease of civilization: make life longer and longer, while people are more and more sick. In a natural environment, people die without aging--or after a very short period of aging. For instance, some markers, such as blood pressure, that tend to worsen over time for moderns do not change over the life of hunter-gatherers until the very end. And this artificial aging comes from stifling internal antifragility." --