[nnx]

"People at the end of their life who claimed to be the happiest with their life were the ones who had spent the most time in this state of flow."

I can certainly believe this.

If you are not familiar with the concept of "flow state" (Samadhi in Hindu cultures [1]), I'd recommend reading the wonderful "Free Play: Improvisation in Life and Art" by Stephen Nachmanovitch [2] over the more famous "Flow" by Mihaly Csikszentmihalyi.

[1] http://en.m.wikipedia.org/wiki/Samadhi

[2] http://www.amazon.com/gp/aw/d/0874776317

[baddox]

Is the goal to maximize how happy you report your life as having been when you're at its end? I could conceive of other plausible goals.