I would imagine that the folk definition of aging is more closely align to your body improving itself vs declining&#x2F;plateauing.<p>For the first 1&#x2F;3 - 1&#x2F;2 of our lives our bodies are building themselves up through growth, but then you hit middle age-ish, hang up the football cleats, and start caring more about your health because &quot;you&#x27;re not a teenager anymore&quot;.<p>The premise that aging is defined as the probability of death feels artificial, or at least out of line with typical understandings of the word.