A Stanford researcher says we shouldn't start working full time until age 40

A woman who is 40 years old today can expect to live another 45 years, on average, while 5% will live to see their 100th birthday. The average 40-year-old man will live another 42. For many people, most of those years will be healthy enough to continue work that doesn’t involve intense physical labor. So why are we still packing all of our career and family obligations into a few frantic decades?