The number isn’t magic--it’s that suddenly a man is overwhelmed with a series of life changes. A man near forty has reached the time in life when he--and others--can notice the physical changes in his body. He likely is near the end of career advancements, and he is acutely aware that he is now in a different generation. 

He can do some things to keep his body in shape, but he cannot stop the aging process. He cannot deny a gradual hair loss and color change, as well as changes in eyesight, reflexes, muscle tone, and weight shift. Life slowly but certainly starts sliding downhill. In addition, he may be having trouble in his marriage, with teenage children, and with aging parents.

He is facing the fact that he may never succeed as he dreamed. A man's self-worth is tied to his work satisfaction. Yet culture values youth and production. For the first time he faces the reality that he can be replaced, and that is frightening. And all because he has become older!