What is the theme in The Corrections by Jonathan Franzen?

Retirement and the elderly is a dominant theme of the book and a common problem in society. Both Enid and Alfred have always looked forward to their retirement. Enid wanted to travel and have a good time. Alfred always thought that his retirement would consist of hunting, fishing, and recreation. He buys a shotgun for that purpose. However, it did not work out that way for either of them. Alfred just sits in his chair in the basement hour after hour.