The simplest answer may also be the best: there's a lot to learn. And it seems that as society becomes more complicated, there's more you must learn to survive.
There is a strong evolutionary advantage to taking care of our sick and elderly -- experts are very hard to train. As medical care improves we can afford to invest more time (childhood) and energy into training increasingly specialized experts.
There is a strong evolutionary advantage to taking care of our sick and elderly -- experts are very hard to train. As medical care improves we can afford to invest more time (childhood) and energy into training increasingly specialized experts.