"The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science"
https://www.amazon.com/Brain-That-Changes-Itself-Frontiers/d...
Statements above are based mostly on The Brain That Changes Itself by Norman Doidge[1] which I highly reccomend. Plus just listen to some old folks that you can tell are still quick - Warren Buffet 86, Chomsky 88, James Harris Simons 79 and so on.
1. https://www.amazon.com/Brain-That-Changes-Itself-Frontiers/d...
I know some coders in their 60s that just like you have a fresh mind and are still eager to learn new things.
I believe association with older people being less capable of mental task and creativity stems from how our society works (or rather worked). People used to do the same job, then become some grandpa with not much input or challenges to keep their brain active. It is quite well documented at this point[1] that when you keep challenging your brain there is not all that much degradation coming with age. It's just that as you get older it's becoming harder to present something really new to your brain - it will tend to view it through existing patterns and use shortcuts that you already have. That's why picking up some new language (not just programming lang) just for the sake of learning something new is a good idea (but what for? could be for fun - dopamine is a lot of fun)
* The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science - Norman Doidge ( http://www.amazon.com/The-Brain-That-Changes-Itself/dp/01431... ), great book
Other good books in similar genre
An Anthropologist on Mars: Seven Paradoxical Tales : Oliver Sacks http://www.amazon.com/An-Anthropologist-Mars-Seven-Paradoxic...
The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science: Norman Doidge - http://www.amazon.com/The-Brain-That-Changes-Itself/dp/14915...
http://www.amazon.com/The-Brain-That-Changes-Itself/dp/01431...
Also, the part about biohacks and bio-weapons, reminded me of the movie Prometheus.
The book "The Brain that Changes Itself" sites a number of examples that often border on the bizarre.
https://www.amazon.com/Brain-That-Changes-Itself-Frontiers/d...