I wouldn't worry too much as long as you are decently educated and keep educating yourself, as if you'll feel such a big need to "get back on top" we are getting closer and closer to manipulating physical and mental capacities with certain substances.
The physical peak bar rising up is most obvious in bdybuilding, as allways, as these guys are ready to experient with anything in order to improve lol.. Some of the guys reach their best shape well into their 40's and some show tremendous results even above 50, so it depends..
I knew one mathematics teacher. She was about 75 at that time. Of exceptional sharpness, she said she's kinda sad as she doesn't have what to talk about with people of her age so she went in various events to communicate with young people. She attended some kind of intellectual capacity "hightening" courses too, where people would meet and solve a very very difficult equations for like 24 hours non stop, sort of a small tournaments, etc.. Anyway, if I'd manage to be that sharp at that age I wouldn't worry about my mental abilities at all.
Oh and what a huge book shelf she had at her house.
Edited by VidX, 20 April 2010 - 03:35 PM.