“Beasts that feed on grass
do not fret over a change of pasture;
creatures that live in water
do not fret over a change of stream.
They accept the minor shift as long as
the all-important constant is not lost.

[Be like them,]
And joy, anger, grief, and happiness
can never enter your breast.

In this world,
the ten thousand things come together in One;
and if you can find that One
and become identical with it,
then your four limbs and hundred joints
will become dust and sweepings;
life and death, beginning and end,
will be mere day and night,
and nothing whatever can confound you
—certainly not the trifles of gain or loss,
good or bad fortune!

-Zhuangzi, by Zhuang Zhou, trans by Burton Watson

Aristotle wrote about “happiness” in The Nicomachaen Ethics.  Happiness is one of our most often used words. The term is much used because the condition of being to which is points is unclear.  Happiness is desired by everyone, universally, while amounting to a wide range of conditions.  Different strokes for different folks, is one way of expressing it.  Each of us desires to-be-happy, while being uncertain of what would make us happy, result in fulfillment, deep satisfaction, or whether happiness can be directly pursued.  Many possibilities of circumstance affect us superficially, momentarily, briefly.  Money, reputation, professional titles, are some of those.  Upon reflection would such be enough to “make me happy?”

In this segment from the Zhuangzi, Confucius asks Lao Dan about the means by which a human being could arrive at a state of being that is “as good as it gets,” perfection.

Lao Dan replies that a grass eating mammal does not mind a change in pasture. Nor does a fish object to swimming along another fork in the stream. Changes within the boundary of the nature of these creatures are accommodated with hardly any notice.

In this world,
the ten thousand things come together in One;
and if you can find that One
and become identical with it…

Gnothi Seauton. Know Thyself was inscribed over the entrance of the temple of Apollo at Delphi.

That sums up the matter.