In my late thirties, I noticed a decline in my problem solving ability. However, I began to exercise more, and get good sleep, and also worked on problems that

In my late thirties, I noticed a decline in my problem solving ability. However, I began to exercise more, and get good sleep, and also worked on problems that were more interesting to me, and I found that not only did my problem solving ability not decline when compared to my younger self, it was actually better since I could bring years of knowledge and experience to bear on the problems. Sometimes, there is a lot of fatalism about growing older, however, if you can take of your body, you can find you are often better than you were at a younger age.