Having read the blueprint, I was interested to see that there is a suggestion to make certain you keep your mind active (10. Use Your Mind/Brain) to aid with overall health and well-being.
I took this to heart and decided to pick up the guitar again after several years of not practising (I was a self taught teenager and used to throttle the hell out of a series of acoustics!), and I have found it a welcome addition to the change in lifestyle and I'm certainly picking up harder chords and changes much quicker than I used to. I'm still self teaching though, and there are definitely a few bum notes in there!
As an aside, I have also taken a major decision to quit my job and undertake a PhD for 3 1/2 years, starting in October 2013. Now, I'm pretty certain my brain will get a workout doing that too! (but it may not aid the relaxed primal lifestyle - stress, stress, stress, data, data, data, stress, stress stress!)
The reason I mention the 'brain workout' is that the majority of information or commentary on here is to do with eating and exercise, so I thought it would be interesting to see what people have done to make sure their brain gets a workout to aid their lifestyle. Have you done as I have and re-took up an old hobby, or are you learning something new and if so what and how is it going for you?