Because more people survive childhood and what used to be the riskiest time for our health, more people will live long enough to reach old age. Indeed, the longer you live, the less the modern world can help your continued survival. This can be neatly demonstrated by looking at historical differences in life expectancy at different ages. A baby born today has a life expectancy of three decades more than one born two hundred years ago. But if you consider someone aged sixty today versus someone aged sixty in 1813, the difference in remaining life expectancy is down to about seven years. Okay, seven years is still a meaningful figure, but it is a lot smaller than thirty years. And as people get older still, the historical difference in remaining life expectancy drops and drops.