I've been re-reading Science of Survival lately and have been reminded of the importance of creating pleasure in a Life.  The kind of pleasure that results in increased survival; a better life.  It can be relegated to the back burner when things get hard or stressful but that's exactly when some time should be set aside to bring some pleasure into existence.  Bliss, comfort, enjoyment, joy, satisfaction, thrill, ease, entertainment, felicity, game, gladness, gusto, kick, relishment, revelry, spice, zest.. any variation on the theme can change a life.

And if you are reading this but can't buy the book, most libraries have the basic L. Ron Hubbard or can get them via inter-library loan.