Brains work best at age 39
It seems that there is this material that works as 'a coating for the neurons'. Kinda like the plastic coating around electricity cables. It helps to process signals between body and brain quickly. After 39, the body slowly stops reproducing this material, hence you get slower.
Well darn, I thought I was nuts now, 5 years from now I'll be even crazier! Combine that with another 5 years of Internet development and it becomes clear this blog will turn into one hell of an intriguing virtual philosophical playground. Stay tuned!