Shakespeare's seven ages of life begin with youth and progress through old age, which he describes as a period of second childhood when we live in oblivion, our senses largely gone. In Shakespeare's day in the late sixteenth and early seventeenth centuries, few people survived to an age we would today consider the seventh stage of life, as life expectancy at birth would have been between 25 and 30 years. Of those who made it to old age, many had to continue working until shortly before their death in order to meet their basic needs. Today, life expectancy is three times that of Shakespeare's era in the developed world and is nearing that in many of the developing countries. And when most people reach the final stage of their lifetimes today, what we now call retirement, their senses are still vitally intact and their lives are not all that different than those they lived before crossing into old age. But as our life expectancies have lengthened, our societies have grown older. As we look to the future, we expect them to grow older still.