Nick Haslam is a professor of psychology at the University of Melbourne. The views expressed in this commentary are solely those of the writer. CNN is showcasing the work of The Conversation, a collaboration between journalists and academics to provide news analysis and commentary. The content is produced solely by The Conversation.
(CNN)Middle age is often seen as life's pivot point. A hill has been climbed and the view over the other side is unsettling. As Victor Hugo said: "forty is the old age of youth" and "fifty the youth of old age."