My dad used to put this as "the older you get, the older you get." At first I thought this was just dad humor (as in, "the more you weigh, the heavier you are") but he explained the that the saying referred to life expectancy going up the longer you survived common "bottlenecks". Obviously at some point the longer you live raises the chances of death but earlier in life, as you get past birth, childhood diseases, the higher risks of adolescence, and work- or war-related injury/death as a young adult, your statistical life expectancy goes up.
