I love the way that the Duke's character goes trough a few different stages that every man (and woman) goes trough in life. Have I done enough? Is there any excitement and adventure left in my life? How do you, as an individual, top an accomplishment like landing on the Moon? I don't think this is something that only happens at this age, but at any point one feels insecure or sad, or even bored. The way he accepted his feelings and sought out support provided a sense of catharsis for the viewer.
