I agree with you: what do people think happen to the brightest and the best from a few decades ago? They grow old and retire, of course. Perhaps the reason they don't sound like experts to younger folks is because they've become experts in a field we don't care about: how to view life once you have the proper perspective. After a certain point, how many lines of code or how fast your site can scale takes a back seat to how to lower your blood pressure and how to maximize your enjoyment from "simple" pleasure like family and food.