Happiness and enjoyment are easily confused because they mostly feel the same.
Their major difference though seems to be the duration of the feeling and the
ease by which the state may be entered.
Happiness seems to be more long-lived while enjoyment seems to me short-lived.
Happiness seems to be mostly independent of the circumstances while enjoyment seems to
be mostly dependent upon the circumstances.
It seems like a worthwhile endeavor to explore where we invest our time, whether
it is in happiness or enjoyment, and evaluate the results of our investment.