An aging academic grapples with losing his mental sharpness:
[B]rains are already heading downhill by one's early 30s, even late 20s, some parts faster and more precipitously than others. The prefrontal cortex where a good chunk of YOU resides is last to develop (thus helping explain why teenagers are teenagers) and first to start its slow drift and then increasingly rapid plunge downward. Luckily, I had lived more than twice 30 years in blissful ignorance of that fact. I make sure to tell my younger colleagues about it lest they be caught unawares like I was. How could I have been surprised though? Why should the brain be any different from the now minuscule muscles I used to run with?
The Dish 