Imagine being born into a world where half the children around you never reach adulthood — and no one finds that unusual. For most of human history, that was simply life. And living into your 70s or 80s was the exception, not the norm. Life expectancy is one of the clearest ways to understand how human life has changed — but only if we define it carefully. It does not describe the maximum age people could reach. Instead, it reflects the average number of years a newborn could expect to live based on the age-specific ...Read More