Most of us, save for the most morbid, don’t sit around thinking of how short life truly is. I submit that there is value in contemplating this very thing. If we maintain our health and are genetically blessed, we have at most 90-100 years on this spinning ball of dirt. In the United States, the average lifespan for a man is 75.6 years, and a woman is 80.8. For all of the advances in Western medicine, that still leaves Americans curiously low at number 36 on the list of lifespan by Country (Wikipedia). In the grand scheme of things, 75-80 years is not a lot of time. Take away from this the fact that our first handful of years is not especially productive, and we wind up with less than 70 years to make a difference in our world.