Let T be the life span and t be the age. Let s = T - t. Remark 1: dt / s is small when t is small. Remark 2: Perception of s (call it p) is in reality a funct

Let T be the life span and t be the age. Let s = T - t. Remark 1: dt / s is small when t is small. Remark 2: Perception of s (call it p) is in reality a function of t. For small t, p(t) is perceived to be near infinity. For t > 40, p(t) rapidly decays to a small number.