I've had time to think this one over, and I'm not sure that a system that allows a person to stop making a significant contribution to society at age 41 is necessarily desirable.

Why should society have any say in what point a person stops making a "significant contribution to society"? It seems to me that it would be each individual's choice as to what contribution to society they make. I know of many people who live their whole lives working in our society without making any significant contribution other than filling a seat. And anyway, who says retiring leads to a less significant contribution to society? Retiring merely means to not have to work for money anymore, freeing up personal time for things like volunteering, navel contemplation, hobby chasing, etc. It seems to me that an individual's character is more important in the determination of their contribution to society than the length of their employment, or the degree of their education. I think the time you spent "thinking this over" may have been better used painting the garage or something else that would be a "significant contribution to society".

Harley