Midlife crisis

 What are some of the biggest challenges faced by adults in middle adulthood (roughly ages 40-65)?  Have you ever known anyone who experienced a “midlife crisis?”  If so, don’t name names, but describe that person’s behaviors.  If not, think of an example you’ve seen in a book, movie, or TV show.  What would theorists such as Erikson or Levinson say about such behaviors?