I ran across a similar type of article today. Now I'm not saying that you shouldn't work forever. If you truly love your job or you want to stay mentally and physically active, then by all means go ahead. Both of my grandfathers worked well beyond the years that they needed to. One sold his business, retired for a week and then went to go work for the person that he sold it to for another 10 years. His doctor told him that he probably just added another 10 years to his life. He lived to be 96. I think the doctor was right!
I do agree with the article that continuing to work later into life does make you more mentally and physically sharp, along with boosting ones moral and psyche. However, when you work into those later years, you need to do them on your own terms. Working because you have to and working because you want to are two completely different mindsets!
I've also never quite understood the idea that you basically go home and sit on the couch during retirement. Maybe this is an old generation theory, but retirement doesn't have to nor should it be that way. If anything it should be the opposite! Your retirement should be filled with exhilaration! Reading, learning, traveling, and working-out should thoroughly consume your time. Have you seen the world? Have you read all of the books? Have you learned every language? Are you in the best shape of your life?? Unless you're fucking superman the answer to all of these are no! So how come you can't find enough to do??
So why do you think you should sit on the couch watching tv all day?? Now if you want to semi-retire doing what you love and then also devote 6 months of every year to the above activities than that sounds like heaven to me. You should have a nice nest egg in case you can't work, and then you can use the money that you make for 6 months to do all of the above activities. You have one life, LIVE IT!