http://social-quotient.info/sq.4mg.com/brainpower.gif
Much less clear on how accomplish that.
Edit: To elaborate, I know exactly what I need to do to stay physically fit into old age and how to monitor my physical fitness - I know immediately when I get winded more from my regular run, my lift numbers drop, or I can't reach my toes.
The scary part is if I stop working out for more than 2 weeks, I see dramatic and rapid declines.
So how do I monitor my mental health? Is it possible to keep improving it? Do I do dual-n-back (studies inconclusive), do I learn a languge/to play piano, do I memorize 5 words a day?