Humans are born with an expiration date. From the moment of conception, we’re assigned a shared fate — that someday, in some way, we all die. It used to come earlier. In ancient Roman times, people could expect to live 30 to 35 years. By the mid-20th century, life expectancy in the United States had risen to 65 for men and 71 for women. Today, the average American life span hovers around 78 years, though that’s far from the bounds of what is possible.