Yes I heard that too, still don't agree and emipirical evidence is the strongest of all! Maybe when one is in one's 70's or 80's. If anything I think I can now read faster, remeber more and get the hang of mental and coordination tasks quicker than ever! My reasoning for this is that in later life one is building on knowledge already present rather than having to learn everything afresh such as when one leaves school. Then again I work in IT and that requires constant and unrelenting research to stay on top of technologies and stuff.