Comment by cm2187

The reality is that most people's mental abilities have started to decline by this age, particularly the capacity to learn new things. That makes this story all the more remarkable. Part of that I think is certainly as you suggest, that the brain is a muscle, you need to use it to keep it fit. But you can't escape nature either. To keep the muscle analogy, you won’t compete as an athlete at 72 no matter how fit you remain.