Going Paleolithic
In his thoroughly enjoyable Science In The Capitol trilogy, Kim Stanley Robinson (who happens to be my favourite author) talks about a concept called “The Paleolithic Life”; something he also spoke about in a Google Tech Talk on Climate Change (at ~50min in). The idea is that there are certain activities engraved in the mind of every human, which result in joy and happiness. These are the things the paleolithic man did during his waking hours, things nature rewarded him for by making him feel alive and capable and good, thus helping him evolve and aiding his development.